Amm i fattt??? i thinkk i ammm :(?

okayyy so i was realllyy looking fowardd to wearingg a bikini this summerr but noww i cantt cause im fatt i weigh 135 an am 5'6? isnt that on the chubby sidee? by thee wayy im 15 yearss oldd, do youu know anyything i can do to tonee up myy bellyy?