Git is a Source Control versioning tool for software development.
When you develop new features or a bug fix, it is good practice to run in a new branch.
When you are ready to update the server with your new branch, you would run git push
Git will tell you that you are in a new branch and so you need to set up tracking (link your local to remote branch) to enable push and pull to know where it should be linked to.
Did you mean?
git push -u origin <branch>
To give Git a clue and avoid asking in the future, just give this config a go.
git config --global push.default current