That fantastic Kateliya!! Crowds are crazy at the start line but most races are pretty good at keeping things organized and moving. When you registered, they probably asked you how fast you expected to finish. If so, its because they are having people start depending on how they expect to finish. The slower you expect to race, the further back your corral will be. Once you start racing, crowds won't be too much of an issue, people will quickly spread out based on speed. Finishing the race will be a real high, I guarantee you will be back for more races! Congrats and good luck!!