Hi!
Well, I think it's not complicated. I am not an expert (I'm an architect
), but I'll try to explain what I think it's correct.
1. The best and absolutely correct is:
I noćas gledam u zvezde, pitam se šta je sudbina. (like in indirect speech)
2. You'll put the quotations when you want to make a question, like in direct speech, when you pose a question, usually to someone else, aloud.
example:
Noćas gledam u zvezde i pitam ga: ,,Šta je sudbina?"
If you say:
Pitam se šta je ,,sudbina" , it would sound like you are retailing the words of some other person what he/she think is destiny, what someone else has said about the destiny. If you say: Pitam se ,, šta je sudbina'', it means you are repeating (ironically) the question someone else has said.
3. If you want to stress the question and not the first part of the sentence, you can do it by putting a hyphen, like a little pause in speech:
I noćas gledam u zvezde, pitam se - šta je sudbina?
you separated it, so I think you must put the question mark.
So it is 1. or 3. in your case.
I so on the net people writing "....", but if you open any book in Serbian, you'll never see that, only ,,....".
(I don't have even the down quotation on my keyboard, I would have to write it "... " like in English!)