It's kinda hard to say what you should do. Getting drunk beforehand is one thing as liquid confidence does live up to it's name on occasion. But before you down that first drink, ask yourself this:
Why did you agree to go?
Your motive should at least somewhat determine your behavior. For example if you said yes because you felt like your friends would end up in trouble and you wanted to keep an eye on them, then yeah, stay sober. If you said yes because you're at that point where you're asking yourself: "man, these kinds of places are fun for everyone else, why are they NOT fun for me?" then sure, get a little buzzed before you go.
If you're going just to try it, to say you've been there and to have a valid response when they try and demand you go again, (my friends still do that with Strip Clubs. "I don't like them." "HOW do you know you don't like them?! You've NEVER BEEN to one!") then getting drunk or at least buzzed is kind of a prerequisite. Dunno what country you're in but it's kinda like going to TGI Friday's or Applebee's or whatever: the food tends to exist and be what it is because of the alcohol. It tastes better due to alcohol, it's in the portions it is so it can extend the amount of drinks you buy, all that stuff.
Booze is an integral part of a club because it not only gives you a reason to not give a damn, but it can also suddenly make a place that sucks when you're sober, become fun. Loud music, glaring lights, people packed so close that you have little semblance of personal space...I can definitely see where that kinda stuff would suddenly become awesome or at the very least tolerable when seen through beer goggles.
So yeah..ask yourself why you're going. If it's to have the club experience, then you might as well have a drink or two. I don't think you have to get totally hammered, but that seems to be what everyone else does so I'm not sure. Just figure out the reason and then if it seems applicable to drink, just go on and have a few.
