commit a un branch code example

Example: commit to a new branch

git checkout -b your-new-branch
git add <files>
git commit -m <message>

First, checkout your new branch. 
Then add all the files you want to commit to staging. 
Lastly, commit all the files you just added. 
You might want to do a git push origin your-new-branch afterward so your changes show up on the remote.