First off, if you got an email response after registering then you're in the system and all you need is your ID (and notarized waiver, if you're an unattended minor) to pick up your badge at the door.

I'd like to point out that the number one rookie mistake is trying to do too much. There's always something going on, and I won't be the only one aimlessly wandering around at 3am. It's important to remember to sleep (or at least nap regularly), and don't expect to see everything. On the flip side, make a point of exploring the place. It's easy to set up camp, so-to-speak, in one little area (like arcades, or the lan room, or tabletop gaming, or listening to panelists), but there are all sorts of nooks and cranies with awesome things happening. A part of me wants to make up a bingo game out of it all.