Tutorials on YouTube:
Git and GitHub
How to create a local git repository and connect it to a newly created github repository.
This video shows you what to do if you try to push a local repository up to the remote and there are conflicts.
How to fork a github repository, clone it, branch it, edit it and do a Pull Request on your edits.
How to add additional repositories to your github pages as if they are sub directories. Note: This tutorial assumes you already have GitHub Pages up and running.
Go to the CodeLoveCode playlist on YouTube
Download this handy, dandy, cheatsheet.
Git Cheat Sheet
Get up and running in minutes with create-react-app