30 Days to Claude Code

What Claude Code is. Claude Code is Claude — the same AI you might already use in a browser — running inside your terminal. The difference matters. In a browser tab, Claude can only see what you paste in. Here, with your permission, it can read your files, create new ones, run commands, and help you build small tools. Everything stays on your computer. You’re always the one deciding what it does.

Open the Terminal. On your Mac:

1. Press Cmd + Space (this opens Spotlight search).
2. Type Terminal.
3. Hit Enter.

A window opens with some text and a blinking cursor. That’s the terminal. You did it.

You’ll see something like this:

yourname@MacBook ~ %

This is called the prompt. The computer is waiting for you to type. The % (or sometimes $) means “I’m ready for instructions.”

What is “typing a command”? You type words at the prompt, then press Enter. The computer does the thing. That’s the whole interaction.

Try this. Type these letters exactly and press Enter:

pwd

You’ll see something like /Users/yourname. That just told you which folder you’re currently “in.” More on that tomorrow.

Install Claude Code. One command, once. Like getting a passport: you do it a single time, then you just travel. Copy this line, paste it into your terminal (Cmd+V), and press Enter:

curl -fsSL https://claude.ai/install.sh | bash

(On Windows, open PowerShell instead and run curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd — the rest of the program works the same.)

You’ll see text scroll by. When it finishes, you should see “Claude Code successfully installed!” You don’t need to install anything else first — the installer brings everything it needs. If something goes wrong, the official troubleshooting is at code.claude.com/docs/en/terminal-guide.

To check it worked, close the Terminal window and open a new one, then type:

claude --version

If you see a version number, you’re set.

Log in (first run only). The first time you type claude, it will ask you to sign in — it opens a browser page, you approve it, and you’re back in the terminal. It uses your existing Claude account (a paid plan; Pro at $20/month is plenty for this program). You won’t be asked again.

If anything ever looks off — weird errors, claude not found, login loops — there’s a built-in checkup:

claude doctor

It checks the installation and tells you what to fix, in plain language.

You’re the one deciding. Claude will sometimes suggest commands, and sometimes ask permission to change a file. You are never required to say yes. If anything feels uncertain, you can ask what a command does before running it, ask Claude to explain its plan first, or just close the window and come back tomorrow. Nothing breaks if you pause.

OK. You’re ready.

Open the terminal (Cmd+Space, then “Terminal,” then Enter).

Type:

claude

Press Enter. Claude Code starts up. The prompt changes. Now Claude is listening.

Type this and press Enter:

Hi Claude. I'm brand new to the terminal. Can you tell me where I am in my computer right now, and explain what that means in plain English?

Read Claude’s answer. Then ask:

What's in this folder? Show me as a simple list.

When you’re done, type:

/exit

and press Enter. That closes Claude. You’re back to the regular terminal prompt.

Today, no Claude. We’re just going to practice moving between folders, because folders are where everything lives.

Three commands. That’s all you need.

pwd

Stands for “print working directory.” It tells you where you are. Try it.

ls

Lists what’s in the folder you’re in. Try it. You’ll see things like Documents, Downloads, Desktop.

cd Documents

cd means “change directory.” It moves you into a folder. Try cd Documents, then run pwd again. See? You moved.

To go back up one level (out of Documents, back to your home folder):

cd ..

The two dots mean “the folder above this one.”

To jump straight to your home folder from anywhere:

cd ~

The ~ (tilde) is shorthand for your home folder.

Practice. Use cd, ls, and pwd to wander around. Go into Documents, then Downloads, then back home. Get a feel for moving.

Today we’ll create a folder where you’ll do all your practice for the next 28 days.

First, get into your home folder:

cd ~

Now start Claude:

claude

Ask Claude:

Please create a folder in my home directory called claude-lab. Inside it, create a file called reflections.md with today's date as a header and a short note saying this is where I'll track what I learn.

Then ask:

Show me what you created so I can see it.

Exit Claude with /exit.

Back at the regular terminal, navigate into your new folder:

cd ~/claude-lab
ls

You should see reflections.md.

Find any document on your computer you’ve written recently. Notes, a draft, an email you saved, anything with text. If you can’t think of one, just use the reflections.md you made yesterday.

Get into your claude-lab folder:

cd ~/claude-lab
claude

Ask Claude:

Read the file at [paste the full path to your document] and tell me three things: What's it about? What's the main point? What questions does it leave unanswered?

Try a follow-up question based on what Claude said.

Open Claude in your lab folder:

cd ~/claude-lab
claude

Ask Claude to create a messy file:

Create a file called raw-notes.txt and fill it with about 15 random unorganized notes. A stream of consciousness mix of ideas, errands, questions, and observations. Make it look like real messy notes.

Look at the file (ask Claude to show it to you, or open it in Finder if that’s easier).

Now ask:

Look at the messy notes you just made. Find the themes hiding in there, then reorganize everything into a clean outline. Save the clean version as organized-notes.md.

You can ask Claude questions about your own computer that would normally take a lot of clicking around.

cd ~
claude

Try these one at a time:

What are the 10 biggest files in my Downloads folder?

How much free space do I have on my hard drive?

What apps do I have installed?

What's been modified in my Documents folder this week?

Pick one answer that surprises you and ask a follow-up.

cd ~/claude-lab
claude

Ask Claude:

Take a look at everything in this folder and tell me what we've built together this first week.

Then:

Add a section to reflections.md called "Week 1" with a short summary of what I learned and what still feels confusing.

Finally:

What's one thing I should try this week that I haven't tried yet?

Find a long document you’ve been meaning to read or process. A report, an article you saved, meeting notes, anything.

cd ~/claude-lab
claude

Read the document at [path to your document]. Give me three summaries: one sentence, one paragraph, one page. Then tell me what assumptions the author is making without saying so directly.

Pick something you have in one format and ask Claude to convert it to another. For example:

• Messy meeting notes into a clean checklist of action items
• A wandering brainstorm into a structured proposal
• A long email chain into a one-paragraph summary
• A list of names and numbers into a formatted table

Here’s what one of these looks like in practice. If you start with messy notes like:

- call jen
- budget weird
- maybe move launch
- ask about signup bug

You might ask Claude to turn them into:

## Action Items
- Call Jen
- Investigate signup bug

## Decisions Pending
- Whether to move launch

## Finance
- Review budget discrepancy

Try two of these.

Find two documents about a similar topic. Two articles, two drafts, two sets of notes.

claude

I have two documents at [path 1] and [path 2]. Read both. Where do they agree? Where do they disagree? If you had to write one document that combined the best of both, what would it say?

If you have a spreadsheet or CSV file, use it. If not, ask Claude to make one:

Make me a CSV file with 25 rows of fake but realistic data about books: title, author, year, genre, rating.

Then:

Look at the CSV. What's the average rating? Which genre shows up most? Are there any obvious errors or weird entries?

Make a cleaned-up version and save it as books-clean.csv.

Almost everyone’s Downloads folder is a junkyard. Let’s start to fix yours — safely.

cd ~
claude

Take a look at my Downloads folder. Tell me what's in there: how many files, what types, how much space they take up, and how old most of them are.

Propose a way to organize this. Don't do anything yet, just suggest a plan.

If the plan sounds good, start small:

Create a folder called Downloads-Archive inside Downloads. Move only the obvious junk into it — old installers, files I clearly don't need anymore. Don't delete anything. Show me each move as you go.

Look at what Claude moved. If you’re comfortable with how it went, do a second pass with more files. Save deletion for later, once you’ve seen how Claude approaches your folder.

Find a folder on your computer that you didn’t create or don’t fully understand. Maybe a project someone shared, an app’s settings folder, or a downloaded codebase.

claude

Take a look at the folder at [path]. Explain what it is, how it's organized, and what the most important files seem to be. Pretend I've never seen it before.

No new instructions today. Pick one real task from your actual life and try to use Claude for it.

When you’re done, update your reflections.md:

cd ~/claude-lab
claude

Add a section to reflections.md called "Week 2" with what I tried, what worked, and what was harder than I expected.

A heads-up before you start: when this guide says “tool,” it doesn’t mean an app with windows and buttons. It means a small file — usually a short script — that you can run from the terminal and it does one specific thing for you. Think “saved instruction” more than “software.”

cd ~/claude-lab
claude

Pick one of these and ask Claude to build it:

• A tool that creates a new dated journal entry every time I run it.
• A tool that adds a line to a running to-do file with a timestamp.
• A tool that shows me everything I’ve changed in my Documents folder today.

Once Claude builds it, ask:

Now show me exactly how to run this. Walk me through it like I've never done this before.

Try running it.

Take yesterday’s tool and ask Claude to add something.

If it makes a journal entry, ask it to also include the weather. If it logs to-do items, ask it to mark them with categories. If it shows your changes, ask it to also tell you the file sizes.

Modify the tool you made yesterday so that it also [thing you want].

Ask Claude:

Make me a tool that does four things when I run it:
1. Checks that a folder called "daily-notes" exists, and creates it if not.
2. Makes a new file inside named with today's date.
3. Puts a header in the file with the date and time.
4. Opens the file for me to start writing.

Run it.

Take any tool you’ve made and intentionally break it. Change a folder name, delete a piece, anything.

Run it. Watch the error message.

Before asking Claude to fix it, ask:

This error came up: [paste the error]. What does it mean? Don't fix it yet, just help me understand what went wrong.

Then ask Claude to fix it together with you.

Git is a tool that lets you save snapshots of your work and go back if you mess up. It has a reputation for being confusing. Claude makes it easy.

If you’ve used an EHR, you already understand the idea: every version of the chart is kept, every change has a name and a timestamp on it, and nothing is ever really gone. Git is that, for your files.

Three words you’ll hear, translated:

• Repository (or “repo”) — a folder git is watching.
• Commit — one labeled snapshot. The label is yours to write.
• Diff — what changed between two snapshots.

That’s the whole vocabulary you need. Claude handles the actual commands.

cd ~/claude-lab
claude

Set up git in this folder. I've never used git before, so explain what you're doing as you go.

Then:

Save a snapshot of everything we have right now, and label it "end of week 3 setup."

Change something in reflections.md. Then:

What's changed since my last snapshot?

Save another snapshot with a label that describes what changed.

In your lab folder, do something “bad.” Delete a section of reflections.md, mess up the formatting, whatever.

Then:

I just messed up reflections.md. Use git to get it back to the way it was at the last snapshot.

See how quickly you can recover. Then look at the trail you’ve built:

Show me the history of snapshots in this folder, in plain language.

One honest caveat: git can only restore what was in a snapshot. A file you never committed, or a folder git isn’t watching, has no time machine. The habit that protects you is cheap — when something feels worth keeping, say “save a snapshot.” Takes five seconds.

This is the big one. Think of something annoying you do regularly. Examples:

• Sending the same kind of email over and over → a template generator
• Forgetting what you worked on yesterday → a daily summary tool
• Wasting time finding files → a tool that shows recent activity
• Manually organizing photos by date → an auto-sorter

Ask Claude:

I have this problem: [describe it]. Help me design a small tool that solves it. Ask me questions about what I want before you start building.

Spend the day building it the way you want it.

Stuck for ideas? Pick one of these and adapt it:

• A morning-brief tool that opens your claude-lab folder, shows what changed yesterday, and creates today’s reflection file ready to write in.
• A “what was I doing?” tool that scans your Documents folder and tells you the five files you’ve touched most recently.
• A meeting-prep tool you point at a folder of past notes — it pulls out anything related to a name or topic you give it.

Don’t pick the most ambitious one. Pick the one that solves the most-annoying part of your week.

cd ~/claude-lab
claude

Look through this whole folder. Make me a cheat sheet that lists every tool we've built, what it does, and exactly how to run it. Save it as my-tools.md.

Use one of your tools today as part of your real day.

Pick a folder you work in often. Maybe for a job, a hobby, or a side project.

cd [path to that folder]
claude

I want to make a CLAUDE.md file for this folder. It should tell future-you (next time I open Claude here) what this project is, how it's organized, what I care about, and any rules you should follow when helping me. Ask me questions, then write the file.

Now every time you open Claude in that folder, it’ll automatically read this file first.

For one day, every time something annoys you on your computer, write it down. One sentence per annoyance. Something small that takes too many clicks, too many tabs, or too many minutes.

Real ones, from real clinicians: “Prior auths for ADHD meds take 20 minutes each — I write the same letter every week.” “I can never find the right Vanderbilt or PHQ scoring chart in under three clicks.” “Sports physicals — every form is different, every league wants something else.” “I want a one-pager I can hand a parent about screen time, by age, without ten tabs.” None of these has a vendor. Each is about twenty minutes of building.

End of the day:

claude

Here are five things that annoyed me today: [list]. For each one, could Claude help? What would it look like?

Pick one. Build a fix.

Find a set of files that belong together. A project, a collection of notes, related documents.

claude

Look at all the files in [folder]. Find any inconsistencies between them. Are there things that contradict each other? Information missing in some but not others?

Now make one summary document that combines everything I'd need to know from all of these.

A few days back (Day 23), you wrote a CLAUDE.md — context about a specific project that Claude reads when you open that folder. Today is different. You’re writing a personal preferences document — about how you work, not any single project. File naming, organization habits, what would freak you out if Claude did it without asking. You can hand it to Claude in any session and it’ll adapt.

cd ~/claude-lab
claude

I want to make a "preferences" document I can show you in future sessions. Ask me questions about how I like to work: file naming, where I save things, how I like writing organized, what makes me trust your suggestions, what would freak me out. Then write up a preferences.md based on my answers.

Find something on your computer that isn’t quite working. A script that’s broken, a process that gives weird results, a file that won’t open right.

claude

Work through it step by step:

Something's wrong: [describe]. Before fixing it, let's figure out together what's happening. What do you think is going on, and what should we check first?

Pick something that feels just barely out of reach. Examples:

• Make me a chart that shows how my [data] has changed over time.
• Build me a tiny website that lists all my projects.
• Take my notes from the last month and write a short essay summarizing what I’ve been thinking about.
• Connect this to my calendar somehow.

If Claude can’t do it, ask why and what alternatives exist.

Write a short guide. One page. Explaining the most useful thing you’ve learned this month. Pretend you’re writing it for the friend you have who would benefit most.

Save it in your lab folder.

Bonus: actually send it to that friend.