I recently had the same question, and now have done two races. A couple of good points have been mentioned, but one has been the most important tom me: have fun 😃 Racing is fun! There are riders who take it a bit "too seriously", but there are a lot of nice folks out there too. Don’t worry about where you are in the pack, strategy etc… at first. Just ride. The rest comes later. Now given that I don’t have much race experience, I can say that my riding gets better after a race, and I learn something every time. That, and the fact that its fun, makes it worth while no matter what.
Good luck…and have fun 😃