If it's your first time in a big crowd coupled with still being perhaps a bit less than totally confident that things won't creep up on you then you need to be willing to make the trade-off that a lot of newer riders don't. Be less willing to look good in favor of being more willing to feel good.
In other words if something feels more than a little bit uncomfortable remember to think that it's ok to just bag it, turn around, and try it again next year. Doesn't matter whether that "something" is traffic, pushy riders around you, the road you're on or whatever. You're looking to go and have fun. You won't be having fun if your head is tucked down between your shoulders and other orifices are in semi-permanent pucker mode.
No one else can really know what your skills or comfort levels might be. In ten months time you probably don't really know those things yourself yet. No big deal, everyone else at that time is the same way. But you will know when something feels like it's just a bit more than you're quite ready for. On an open stretch with no one around you and nothing else to bump in to or bump in to you is when you knowingly go about expanding your skills. In a crowd of (literally) thousands who might be getting bitchy about getting to wherever they're going is a time to take it easy.
Have a good time. Wish I was there too [smiley=thumbsup.gif]