I always have a fun time at Studio 54 which is probably why I end up there at least once per visit to Vegas. Which means I've been there a LOT.
First thing - get dressed to impress. For guys this means you have to look sharp. For girls this means you can wear anything - dresses or slutty tops with jeans or probably next to nothing and you'll be fine.
Next - look for the guys in the casino giving out wristbands so you can go in the VIP line and not have to pay. I suspect you may have to be a hot chick to get this, so if you aren't you should expect to wait in line and pay $$ to get in.
Stop at Centrifuge bar across from Studio 54 to pregame drink a bit.
Now go in Studio 54 and get a pricey yet pretty strong for your money drink. Repeat x 100.
Now hit the dance floor! I like how they play retro 70s/80s tunes at the start of the night, then move into recent music and hip hop after that, then move into more techno later on. I don't like techno but at least you don't get it ALL NIGHT LONG. I also am not a fan of the teaser 1 verse of a song and switch but I know others have ADD and do like it. They do continue playing songs that are really good jams or the ones that get the dance floor hopping so at least there's that. Also check out the go-go dancers. They are hot, they are scantily clad, some of them can dance pretty well too. Emulate them and you are golden.
Go back to bar and get more drinks x 100. Consider making out with dudes/chicks as your orientation leads you.
Get into the VIP area upstairs if you can because it is pretty nice. Last time I was up there they had nice seating, including a chaise lounge, and it overlooks the dance floor so you can see what all the lesser people are doing. Feel smug, look down nose at them.
Stumble out of club when they close it down (I have actually been there for a club to close in Vegas. I was surprised that they even close at all!!). Keep drinking at the casino, go home with that hottie you met, or go pass out. It is all up to you - it is Vegas!