How can i loose weight for the end of june? 10 POINTS TO BEST ANSWER!?

I'm 14 and i'm 150 (i know im fat) i want to loose 15-20 pounds for the summer because i want to be able to go swimming and feel good about myself. i don't want a diet, i've tried atkins and sacred heart and none of it actually works. i want someone to yes give me a healthy meal plan but also i especially want someone who knows what excercises i can do to make me loose weight. please be specific not just like "do cardio for 10 minutes" tell me like "run for 10 minutes then bike for 15" and stuff. please, help me. i've been big my whole life and all i want is to be fit. please help me.