...only for good. We're, of course, talking about your will to win. Your driving urge to be the best, no, even better than that, to be the greatest.
Being competitive can start in many different ways. A tough childhood can make you feel you have to beat everybody to simply survive. Being low in your family birth order and fighting for attention could do it. Being different and wanting to fit in or maybe it's just the way you're wired. We can even go back to primal days and fighting for food and other resources.
Don't get me wrong there's nothing inherently wrong with being competitive. In fact, it makes family gatherings way more fun. But if it ruins your day to lose, or worse, to not be first, you might need to damper your fire a little. There are very few things in life, really, that require that kind of energy.
Instead, see every opportunity, win or lose, as a chance to learn something. About yourself, your teammates, your "opponents", the world around you. Nobody wins, or loses, them all. The true champion is the person who comes away better than when they began. Approach your challenges like that and you might find that you actually seek out new arenas, new areas for healthy competition. Just imagine saying, "I think I'll try that. I might stink up the joint at first but I'll get better."
What's the worst that could happen? You'll have fun, make new friends and grow to be a better person.