Some one answer please!?

Hey..im 14..female! im just under 8 stone! i used to be very big but i lost a lot of weight1 a siz 14 dwn to 10..but uv started to eat a little more latley and im very scared of become big again! what exercise can i do at home to tone my body as in a flater stumoch?i also go on the trampline everyday 4 about a half hour! wil this also hel me loose weight! please answer.thanks a lot xx