How do i get thinner thighs and a thinner stomach?

Im soo embarresed of my thighs and my stomach! My thighs jiggle and they have stretch marks and i hate wearin a swimmin suit in public like at six flags or at my friends house because im scared they are like gonna make fun of me or something!!! And if u have any advice on how i can get a thinner stomach and thinner thighs in less than a month pls share! I wld relly appreciate it. And btw this was written by a 13 year old!