I'm 14 and 5'3 I need to lose weight fast!!!!!!

I'm 14 and 5'3 and I weigh 128 pounds, I need to know how to lose at least 15 pounds quick, but the only thing is is that my parents don't want me eating diet food because they say I'm too young for that, which they are most likely right so if anyone knows what types of exercises I need to do and how many minutes please e-mail
Thank you and God BLess