Welcome to ePlaya, Winger!
Keep reading, and you will learn all kinds of things -- some
many you hadn't even thought to ask.
Basically, you camp anywhere you want, so long as you do not interfere with anybody already there or nearby. Granted, there are reserved areas for Registered Theme Camps, but these reservations expire when the event opens to regular ticket holders. (If the Registered Theme Camp has not set up by then, they are considered no-shows.)
There are also Villages you should not camp in without invitation, but I believe those will be marked.
When you pull into a likely spot, you should walk over to the neighbors and say hello, to make sure you and they are reasonably compatible. Loud music tends to be the most common mismatch.
Keep in mind that the loudest dance music is on 2:00 Street and 10:00 Street, near the corners of Esplanade, so if you want to be able to hear yourself think, you may want to camp far from there.