Hi Minor Tom! Good questions. Tamarakay gave you some really good advice. You need not follow your friends all week by any means. In 2008 and 2009 I attended with a good friend of mine, and we roamed together one night (all night!) each of those years, but the rest of the time we did our own thing . . . although we frequently ate at the same time on a daily basis, and so shared the details of our various adventures as we did so.
So if you get along really well with these folks and they welcome you, I'd advise you to go with them . . . but tell them ahead of time that both for your sake and theirs, you're happy to let independence--radical self reliance!--reign, once you've helped set up camp.
Re noise: Ask them about their tolerance for it, where they plan to camp, and in general how they feel about camping near the Sound Camps . The loudest camps are near the Esplanade (the center) and near 2 to 3 o'clock on the map, and 9 to 10 clock, and in/adjacent to the marked Theme Camp areas. It's . . . kind of a noisy city. The quietest places are towards the outside streets, or in Walk-In Camping (which is extremely quiet, but probably not right for one's first time, as you don't know what you're getting into). But other than those places, you're going to get some noise.
The best earplugs for a light sleeper are the white silicone plugs sold in pharmacies. They're large, so I typically take one and tear it in half to make two. They seal out quite a bit, but it's a weird sensation, so I highly recommend trying them at home first.
Finally, unless you're sleeping inside an RV, the light may wake you up at 6:15 (hence the sleeping mask) and the heat will become noticeable in a tent by 7:30/8:00am unless the tent is well-shaded (which might buy you an hour or two), so keep that in mind when you choose a bedtime. On the upside: you can dance all day, so there's no weakness about hitting the hay at 1:00am if you began partying at dinnertime.