I have cellulite and stretch marks....help?

well im 15 and i use to weigh 120 ..now i lost about 5 lbs and weigh 115 and ive been noticing stretch marks below my hip and cellulite on the inside of my thighs....i dont work out or anything. i just wanna know if theres something i can do to lower the appearance of them and get rid of the stretch marks....