Prague visit?

am going to visit the Czech Republic over the summer. I have never been there but I have heard only good things about it. My friends and I want to go out there. We have heard that the night life over there is amazing! We want to go to a nice bar, a bit of a posh place and then to a night club. Can you recommend a place? And where is a place where you meet tourists as well as Czechs? Thanks.