[git] Your branch is ahead of 'origin/master' by 3 commits

This message from git means that you have made three commits in your local repo, and have not published them to the master repository. The command to run for that is git push {local branch name} {remote branch name}.

The command git pull (and git pull --rebase) are for the other situation when there are commit on the remote repo that you don't have in your local repo. The --rebase option means that git will move your local commit aside, synchronise with the remote repo, and then try to apply your three commit from the new state. It may fail if there is conflict, but then you'll be prompted to resolve them. You can also abort the rebase if you don't know how to resolve the conflicts by using git rebase --abort and you'll get back to the state before running git pull --rebase.