What to eat and what exercise you should do to lose weight?

I've started gaining weight over the last 2 years and it really gets me down I want to lose about 2 stone I am currently just past half way over 9 stone I'm 16 so what exercises can do to lose the weight and what food like for dinner I would not no what to eat so I'd eat unhealthily so I'd like to no a few meal Ideas please thank you for ur help