$ git config --global user.name "John Doe"
$ git config --global user.email johndoe@example.com
git clone <url>
if you don't have remote you should add
git remote add origin <url>
for create branch
git branch <name>
for set branch on github:
git push -u origin <name>
git add .
git commit -m "description"
git push origin <your branch name>
git pull origin <branch name>
.