I've been homeschooled since 2nd grade and I'm going to 8th grade public school this year. I go to gymnastics 3 times a week for 2 1/2 hours each time. I speed walk (almost a run) on the treadmill for an hour three (and sometimes four) times a week. I am vegetarian so I guess I eat some more junk food than I should, but I also eat salads, beans, and tofu, etc. I have pocket of fat on my lower stomach that is driving me crazy! When I wear a fitted shirt (or leotard to gymnastics practice) this ugly gut hangs through. I've tried everything to get rid of it. Cardio, diets, strengthening, and such. I'd really like to have it completely gone by next month when I start school. Does anyone know why I can't get rid of it? How do ​I get rid of it? THANKS!

Forget about flattening your abdomen (above navel = stomach; below = abdomen) in a month.
If you are female, you may just have a genetic disposition to collecting fat there, just as some girls have fat hips or butts.
(When I lose weight, the first fat to go is my boobs - how fair is that?)
You are vague about being vegetarian somehow making you eat more junk food? That doesn't follow. Please explain what and how much. And also, cut it out!
And if a vegetarian diet is keeping you hungry, you are probably missing enough protein, so talk to your parent(s) about maybe an egg a day in addition.

Meanwhile, wear dark pants/skirts, and maybe invest in some tummy control panties or one small girdle to go over panties.
Do NOT wear tight pants to try to hold it in. That just makes it more visible.
Others in school will have differences that make yours seem like nothing. I know it always seems like ours is the worst, but it's just not true. Just be a friendly person, being nice to others, and you will be fine.