Setup

Before you can use Git, you need it installed, configured, and connected to GitHub. This lesson is pure setup — do it once, and you are done.

Install Git

macOS

brew install git

No Homebrew? Run xcode-select --install in your terminal — that installs the Xcode Command Line Tools, which include Git.

Linux (Debian/Ubuntu)

sudo apt update && sudo apt install git

Windows Download and install Git for Windows. During setup, select "Git Bash" as your terminal. All Git commands in these lessons assume a Unix-style shell.

Verify the installation

git --version

You should see something like git version 2.44.0. If you get command not found, installation did not complete — try again.

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Configure Your Identity

Every Git commit is stamped with your name and email. Set them now:

git config --global user.name "Your Name"
git config --global user.email "you@example.com"

Use the same email you will use for your GitHub account. This links your commits to your profile on GitHub.

Set the default branch name to main

git config --global init.defaultBranch main

Older versions of Git default to master. This matches GitHub's default.

Set your default editor

If you use VS Code:

git config --global core.editor "code --wait"

If you prefer the terminal:

git config --global core.editor "nano"

The editor opens when Git needs you to write a commit message or resolve a conflict.

Verify your config

git config --global --list

You should see your name, email, and other settings you just set.

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Create a GitHub Account

Go to github.com and sign up. A few tips:

• Choose a username you would be comfortable putting on a resume. It will appear in every URL you share (github.com/<username>/...).
• Use the same email you configured above.
• Enable two-factor authentication after signup — it is required for some operations and good practice regardless.

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Generate an SSH Key

SSH keys let you push to GitHub without typing a password on every command.

Generate the key

ssh-keygen -t ed25519 -C "you@example.com"

• Accept the default file location (press Enter).
• Set a passphrase or skip it (press Enter twice). A passphrase adds security; skipping it is fine for personal machines.

This creates two files:

• ~/.ssh/id_ed25519 — your private key. Never share this.
• ~/.ssh/id_ed25519.pub — your public key. This is what you give to GitHub.

Copy your public key

cat ~/.ssh/id_ed25519.pub

Select and copy the entire output.

Add it to GitHub

1. Go to GitHub → Settings → SSH and GPG keys → New SSH key.
2. Give it a descriptive title (e.g., "MacBook Pro 2024").
3. Paste the key. Click "Add SSH key."

Test the connection

ssh -T git@github.com

Expected output:

Hi <username>! You've successfully authenticated, but GitHub does not provide shell access.

If you see this, you are ready to use Git with GitHub. If you see a permission error, check that you copied the full public key including the ssh-ed25519 prefix.

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Summary

What	Command
Install (macOS)	brew install git
Verify install	git --version
Set name	git config --global user.name "..."
Set email	git config --global user.email "..."
Default branch	git config --global init.defaultBranch main
Set editor	git config --global core.editor "code --wait"
Generate SSH key	ssh-keygen -t ed25519 -C "..."
Test SSH	ssh -T git@github.com