Start Coding with Claude
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Module 3

Setting Up Your Computer

This is the module where your computer becomes a workshop. It involves the terminal — the screen with the blinking cursor that movies use to signal "hacker." By the end of this page, that screen will feel about as intimidating as a text message. Set aside 30–45 minutes.

One honest note about cost before we start

Everything so far has been free, and the terminal and Node.js below are free too. Claude Code — the tool we install at the end of this module — requires either a paid Claude plan (Pro, around $20/month, is plenty for this course) or pay-as-you-go API credits. If you got value from the calculator you built in Module 2, this is the point where a small monthly cost buys you a genuinely powerful capability. Upgrade your account at claude.ai before the Claude Code section below.

Meet the terminal

The terminal is a way of talking to your computer by typing commands instead of clicking icons. That's all it is. Clicking a folder and typing the name of a folder are two ways of saying the same thing — the terminal is just the typed version.

Why bother? Because Claude Code lives in the terminal, and because typed commands are how developers' tools talk to each other. You only need to be comfortable, not expert. Let's open it:

Press Cmd + Space to open Spotlight search, type Terminal, and press Enter. A window opens with a prompt ending in % or $, waiting for you to type.

Click the Start button, type PowerShell, and press Enter to open Windows PowerShell. A window opens showing something like PS C:\Users\you>, waiting for you to type.

Five safe commands to try right now

These five commands look at things and make one harmless folder. They can't break anything. Type each one and press Enter after it.

Terminal 
pwd

1. Where am I? Prints the folder you're currently "standing in" (it stands for "print working directory"). You'll see something like /Users/yourname.

Terminal 
ls

2. What's here? Lists the files and folders in your current location — the same things you'd see in Finder.

Terminal 
cd Desktop

3. Move somewhere. cd means "change directory" — you just walked from your home folder onto your Desktop. Try ls again and you'll see your desktop files. (cd .. takes you back up one level.)

Terminal 
mkdir my-first-folder

4. Make a folder. Look at your actual Desktop — there's a new folder called my-first-folder sitting on it. You made that by typing. Feel free to drag it to the trash afterward.

Terminal 
echo "I am officially using the terminal"

5. Say something. echo just repeats text back. Congratulations — you've used the terminal, and nothing exploded.

PowerShell 
pwd

1. Where am I? Prints the folder you're currently "standing in." You'll see something like C:\Users\yourname.

PowerShell 
ls

2. What's here? Lists the files and folders in your current location — the same things you'd see in File Explorer.

PowerShell 
cd Desktop

3. Move somewhere. cd means "change directory" — you just walked from your home folder onto your Desktop. Try ls again and you'll see your desktop files. (cd .. takes you back up one level.)

PowerShell 
mkdir my-first-folder

4. Make a folder. Look at your actual Desktop — there's a new folder called my-first-folder on it. You made that by typing. Feel free to delete it afterward.

PowerShell 
echo "I am officially using the terminal"

5. Say something. echo just repeats text back. Congratulations — you've used the terminal, and nothing exploded.

Install Node.js

Node.js is a free program that lets your computer run JavaScript — one of the most common programming languages — outside of a web browser. Your QuickBooks dashboard in Module 5 will run on it. We'll install the LTS version, which means "Long Term Support" — the stable, recommended one, not the experimental one.

  1. Go to nodejs.org.
  2. Click the big green download button labeled LTS — the site detects your Mac automatically.
  3. Open the downloaded .pkg file and click through the installer, accepting the defaults.
  4. Quit and reopen Terminal (this matters — the terminal only learns about new programs when it starts), then verify:
Terminal 
node --version

You should see a version number like v22.x.x. If you do, Node.js is installed.

  1. Go to nodejs.org.
  2. Click the big green download button labeled LTS — the site detects Windows automatically.
  3. Open the downloaded .msi file and click through the installer, accepting the defaults.
  4. Close and reopen PowerShell (this matters — the terminal only learns about new programs when it starts), then verify:
PowerShell 
node --version

You should see a version number like v22.x.x. If you do, Node.js is installed.

Install Claude Code

Claude Code is Claude living in your terminal, where it can create files, write whole projects, and run programs for you — always asking permission before it changes anything. It's the same AI you met in Module 2, with a workshop instead of a chat window. Install it with Anthropic's official one-line installer:

Paste this into Terminal and press Enter:

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

Then quit and reopen Terminal, and verify:

Terminal 
claude --version

Paste this into PowerShell and press Enter:

PowerShell 
irm https://claude.ai/install.ps1 | iex

Then close and reopen PowerShell, and verify:

PowerShell 
claude --version

If claude --version prints a version number, you're installed. (Anthropic occasionally updates its install method — if the command above ever fails, the current official instructions are always at code.claude.com/docs.)

Sign in

Type claude in your terminal and press Enter. The first time, it will ask you to sign in — choose the option to sign in with your Claude account, and it will open your browser to connect the account you set up in Module 1. Approve it, come back to the terminal, and you're in.

Troubleshooting: the five most common install problems

"command not found" or "not recognized" after installing

Nine times out of ten this just means your terminal window is older than the installation. Close the terminal completely and open a fresh one — terminals only learn about new programs at startup. If a fresh window still can't find it, restart your computer; that rebuilds the list of installed programs (called the PATH) everywhere.

Windows says "running scripts is disabled on this system"

PowerShell has a safety setting that blocks downloaded scripts. Open PowerShell and run Set-ExecutionPolicy -Scope CurrentUser RemoteSigned, answer Y, then try the installer again. This tells Windows to allow properly signed scripts for your user account only — a standard developer setting.

Mac asks for a password in the terminal but nothing appears when I type

That's normal! When the terminal asks for your Mac password, it hides your typing completely — no dots, no stars, nothing. Type your password blind and press Enter. It's a security feature, not a freeze.

The install seems to work, but signing in fails or loops

First, check that you can log in at claude.ai in your browser — if your session expired there, fix that first. Then run claude again and pick the sign-in option. If the browser window opened but nothing came back to the terminal, close the terminal, reopen it, and try once more. Corporate or public Wi-Fi with strict firewalls can also block the sign-in handshake — a phone hotspot is a quick way to rule that out.

"claude" starts but says my plan doesn't include Claude Code

Claude Code needs a paid plan (Pro or higher) or API billing — a free claude.ai account can chat on the website but can't use Claude Code. Upgrade at claude.ai → Settings → Billing, then run claude and sign in again.

Your first Claude Code session

Let's take it for a two-minute walk. In your terminal, make a practice folder and step into it:

Terminal / PowerShell 
mkdir claude-practice
cd claude-practice
claude

Claude Code opens right there in the terminal. Now talk to it exactly like you talked to Claude on the website. Try these, one at a time:

Say to Claude Code 
Hello! I'm brand new to this. In a couple of sentences, what can you do for me here that the Claude website can't?
Then try 
Create a file called hello.txt in this folder containing a short encouraging note to a business owner who is learning to code.

Watch what happens: Claude Code asks your permission before creating the file. That permission step happens every time it wants to change something — you are always the one holding the pen. After you approve, look in your claude-practice folder: the file is really there, on your real computer.

When you're done exploring, type /exit to leave Claude Code. (Commands that start with / control Claude Code itself.)

What you just accomplished

You used the terminal, installed a programming language runtime, installed a professional AI coding tool, and directed it to create a real file on your machine. That was the hard, unfamiliar part of this course — and it's behind you. From here on, we build things.

← Module 2
✓ Module complete Next: Your First Real Project →