Module 02 — Installing & Configuring Git

Goal: Get Git working on your machine, tell it who you are, and understand the configuration system you’ll lean on forever.

2.1 Installing Git

Windows

Download the installer from git-scm.com and run it. The defaults are fine; the installer also gives you Git Bash, a terminal that behaves like Linux/macOS, which is the easiest place to follow this tutorial. Alternatively, run in PowerShell:

winget install --id Git.Git -e

macOS

The simplest route is Homebrew:

brew install git

Or just type git --version in Terminal — macOS will offer to install the Xcode command-line tools, which include Git.

Linux

Use your package manager:

# Debian / Ubuntu
sudo apt update && sudo apt install git

# Fedora
sudo dnf install git

# Arch
sudo pacman -S git

Verify

On any system, confirm it worked:

git --version
# git version 2.49.0   (your number may differ — anything 2.30+ is fine)

2.2 The first thing you must do: tell Git who you are

Every commit you make records an author name and email. Set them once, globally:

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

Use the same email as your GitHub account so your commits get linked to your profile later. This isn’t a login — it’s just a label stamped onto each commit. (Git doesn’t verify it; the email is purely informational unless you add signed commits, section 2.6.)

2.3 Understanding the three config levels

Git settings live at three levels, each overriding the one above it:

Level	Flag	Where it’s stored	Applies to
System	`--system`	`/etc/gitconfig` (or Git install dir on Windows)	Every user on the machine
Global	`--global`	`~/.gitconfig` (your home folder)	All your repositories
Local	`--local` (default)	`.git/config` inside a repo	That one repository only

So if your work projects need a different email than your personal ones, set the global email to personal, then inside a work repo run git config user.email "you@work.com" (no --global), and that repo overrides the global setting.

See all your settings and where each came from:

git config --list --show-origin

2.4 Configuration worth setting now

A few settings make life much nicer:

# Use 'main' as the default branch name for new repos (modern standard)
git config --global init.defaultBranch main

# Your preferred editor for commit messages (examples)
git config --global core.editor "code --wait"   # VS Code
git config --global core.editor "nano"            # simple terminal editor

# Make Git output colorful and readable
git config --global color.ui auto

# Sensible behavior for 'git pull' (avoid surprise merge commits)
git config --global pull.rebase false   # merge style (default, beginner-friendly)

# Handle line endings cleanly across operating systems
git config --global core.autocrlf input   # macOS/Linux
# On Windows use:  git config --global core.autocrlf true

These all live in ~/.gitconfig, which is a plain text file you can open and read — it’s not magic.

2.5 Connecting to GitHub: SSH keys (the smooth way)

To push code to GitHub without typing a password every time, you authenticate with an SSH key — a pair of cryptographic files: a private key (stays secret on your machine) and a public key (you give to GitHub).

# 1. Generate a modern Ed25519 key pair
ssh-keygen -t ed25519 -C "you@example.com"
# Press Enter to accept the default location (~/.ssh/id_ed25519)
# Optionally set a passphrase for extra safety

# 2. Start the ssh-agent and add your key
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519

# 3. Copy your PUBLIC key to the clipboard
cat ~/.ssh/id_ed25519.pub      # then copy the output

Then on GitHub: Settings → SSH and GPG keys → New SSH key, paste the public key, save. Test it:

ssh -T git@github.com
# "Hi <username>! You've successfully authenticated..."

Never share the private key (id_ed25519 without .pub). The .pub file is the only one you ever paste anywhere.

Alternative: HTTPS + credential manager

If SSH feels heavy, you can use HTTPS URLs and let Git’s built-in credential manager remember a Personal Access Token (PAT). On Windows and macOS the credential manager is installed with Git automatically. You create a PAT under GitHub → Settings → Developer settings → Personal access tokens. Either method works; SSH is the most common for everyday development.

2.6 (Optional) Signing your commits

For teams that need to prove a commit really came from you, Git supports signed commits using GPG or SSH keys. GitHub then shows a green “Verified” badge. This is optional and beyond a beginner’s needs, but worth knowing it exists:

git config --global commit.gpgsign true

Try it yourself

Run git --version to confirm the install.
Set your name and email with the two --global commands.
Run git config --list --show-origin and read the output — find your name and email in it.
(Optional but recommended) Generate an SSH key and add it to GitHub.

Key takeaways

Install Git, then always set user.name and user.email first.
Config has three layers — system, global, local — each overriding the last; local lives in .git/config.
~/.gitconfig is a readable plain-text file holding your global settings.
SSH keys let you talk to GitHub securely without passwords; never share the private key.

Next: Module 03 — Your First Repository