How to lose stomach fat?

I'm 14 and the pool opens in about a month. I'm not fat but I have a bit of a wide waist, I don't know why, and a little bit of fat in my lower stomach. Like a little pooch. I'm really self conscious about my stomach. How can I lose some weight in that area? Also, my legs are SUPER long, and I feel like my thighs are fine, but my lower legs are too skinny? Any way to gain a little muscle in the calves? I feel like my legs are awkward. Thanks[=