If you haven't ridden in a group, you should practice before entering a race because pedaling in close proximity can be unnerving. In fact, it's not unusual in races to get bumped into. If you're used to it, it won't bother you. If you're not, you might crash or cause one. The best way to learn is to join a friendly group ride. Be sure to find the group leader before the ride starts and tell him that you're there to learn. He'll probably ride at the back with you and explain how to ride safely. A key skill is being able to ride a straight line, which comes with relaxation and confidence. It's also best to never overlap someone's rear wheel with your front wheel because, if they have to swerve to avoid a hole or rock, they'll bump your wheel and knock you off. With a little practice, a good teacher and by carefully observing how experienced riders do it, you can learn to safely ride in groups, which will help a lot in races.