In this tutorial, we'll provide a complete introduction to both GitHub and Git. Learn the differences and how to use them.

The second link above will fix that problem. Once the local repo is initialized and a remote is configured, you should be able to run git status, git diff, etc.

Now that you have your repository cloned to your local machine, add (or create) all the code you need for the repository into the new directory and issue the command: git add .