Hello can someone help me with this problem.Every time i talk to someone on Privden they just start the same dialogue (without giving me option to trade or smt like that)

Synth.

Do you mean the BoS Prydwen? If so, I think there are several people that you can talk to if you are a member of the Brotherhood of Steel. I haven't been able to have any dialogue with the rest of the crew members though. I think that's normal.

Just a few people has dialogues, questgivers, mercants and a few other key people.