How can i get a flat stomach?

Ok so im in track but i have a belly, yet i can beat others who are all ripped! I am not the fastest but im quite fast but i wanna look like an athlete too. Everybody expects me to have a great body, but i have a belly which makes me upset.

So how can i get a flat stomach? I like to eat a lot of sweets too, so yea thats a problem(but no soda). So how can i get a flat stomach at least….. oh and im a guy