I'm very beginner in Git. I learned how to use in terminal but now I use SourceTree. Everything was perfectly fine but time for first checkout has come. After checkout I moved forward with my task and now I have this two branches and I don't know how to push later changes to remote. On remote I only see that one I checked out. Should I set `master` to `HEAD`? I can type in terminal, I don't care about SourceTree.

![snippet from SourceTree](https://i.stack.imgur.com/2SUky.png)

Thank you for answers!