Just buy your tickets whenever you have enough cash...It is DEFINATELY worth it!
Don't worry about pissing as everybody just takes a leak in the bushes anyway and just use the pay toilets when you need to drop a duece.
There is TONS of stuff to do...right after wrestling there were wet tshirt contests, they had highland games type of stuff and random naked ladies playing some kind of twister game. The food was pretty damn good over there, expensive but delicious. You can just stop by random tents and strike up a conversation with a group and bam, that'll kill a few hours.
You'll meet tons of new people unless you're the quiet shy type, so going there with a group is not a must. I'm sure you'll make nice with your neighbors or even meet people on the bus ride over there.
Some Mexicans near my camp this year had brought a fuckload of tequila so the amount you're allowed shouldn't matter...I saw plenty of Glass bottles around too even though they're not allowed.
Just buy your tickets and go, worry about sleeping once it's over.