Just warning you all now. Clubs are really demanding and most of the time you only get paid on tips. It's not by the hour or project. You're best off learning to make clothes, build, and such other things.
Well, working in a club is pretty much you being a host/hostess. You're like the greeter and the one who gives people the group tag to wear to sign up for contests that maybe going on. You can be a DJ, the one who plays the music. Those guys get more tips than a hostess/host ever does. As a hostess you're supposed to chat in public, be nice to others, and everything else. You're like a conversation starter for the club.
Some clubs have dancers. These girls(usually?) are just strippers who take off their virtual clothes for Lindens Dollars once they reach a certain amount. (example, 100L is the top, 200L is the pants, etc) i work at a club currently where you are a dancer, but you're also like the host/hostess of the venue. No stripping involved.
You could become a manager, but that usually almost never happens often. A manager can do the whole kick/ban from the parcel/land, hires and fires staff, along various other management tasks. Some hosts and regulars have been known to be able to kick you from the parcel if you act out too bad and break their rules.
Most of the time working in SL pays very little, and having a real life job is much better. Not all of us can have a IRL job, though. For those that cannot, there are a load of freebie shops and freebies in shops if you join their group.