Get you started with Git from zero (note that if you already use Git, this workshop will be too basic for you). We'll look into git on a command-line level & GitHub online version.

Introduction, set-up & configurations
Working locally: Create a repository, clone, edit, staging commits, commit & push
Working with your history, logs and diffs (including undo changes)
Working in a project: Forking, branching, pull requests, fetch, merge, pull & push

In the most likely case, we have time left:

Resolving common problems
Collaborating tactics
Gitignore files