I’ll flesh this out later, but:

  1. git add . to add everything, or git add FILENAME to add files one by one.
  2. git commit -m "Message here" to make a commit, a.k.a. save things into your repository
  3. git push to send everything to GitHub - you’ll use git push -u origin master the first time
  4. Did it not work? Did you get a message about git pull? That means there is new data on the repository that isn’t on your computer. Running git pull by itself will sometimes send you into a weird text editor, hit ESCAPE then type :wq and hit enter. I know, it’s dumb. You could also run git pull --rebase to avoid that. Then try to commit and push again.