Does přítelkyně=girlfriend or friend or both?
In my experience as a foreigner speaking Czech in CZ, calling a girl přítelkyně was always assumed to mean girlfriend. I've never been in a context where this was interpreted as "friend".
If you are male among young women than yes. Note that even the English word "girlfriend" sometimes just means a female friend of another female person.
Is there a vocative case for Žofie?
Yes. And it is .... Žofie.
in this exercise i feel like i translated the same sentence four times.
it is level 1 Thou
Certain sentences are deemed too hard for Level 1 (by the automatic Duolingo process, so we do not even know which ones). So there is fewer sentences to choose from so you may get more repetition.
I'm on level 3 and still get four or five identical questions.
They are identical in English, but they differ in Czech :)
Yes, way too many "you are a good friend" questions.
I have learned to live with it. Good advice for all learners, I'd suggest. :-)