I'm going to Leeds for my 18th birthday and need advie on where to go (or not) lol?

I've been to Leeds before but only shopping, so know my way around the city centre but not well, and not on a night time. I need information from people that have been to Leeds on a night out. Good places to go? Where are they? Places not to go? We're all students so don't really want to go to expensive places. Any help would be really appreciated.