"Are you a university student?"
Ka is the particle for a question yes, although its not necessary if you have an upwards inflection on the sentence. Lots of implying things in Japanese.
And it seems like the pronouns are almost always omitted. They typically leave out the subject all together or else use the person's name instead of pronoun, even if they are talking to them. So you would say maria-san (or whoevers name) even if you're talking to Maria. Or you wouldn't have a subject.
The problem is it would be grammatically incorrect in english to leave out a subject, and it flows weird if you contantly say someones name... but you wouldn't really say anata in that sentence. It would be obvious in the situation.
What I have heard is that using pronouns too frequently comes across as a bit assertive. So you address people typically by name if you can't tell who the sentence is about in context. But otherwise no subject.
So two people talking would probably never use a subject at all talking about themselves, but if they brought up something or someone else then they introduce the new topic and then don't have to say that again unless they change subjects again.