It is always best to see your doctor before beginning any diet/exercise regimen. Especially at your age, please let your doctor ensure that the amount of weight u want to lose and ur method 4 losing it is proper for ur body and age.
Weight loss doesn't happen PRONTO....... it takes time.
There are a variety of exercises you can do to lose weight, but you can't do the same thing every day and you have to eat well, also.
How about getting on one thread and let us help you, step by step, rather than jumping from one thing to another.
First you have to determine if you are really overweight, and if so, how much weight you need to lose; then you have to decide on a diet and exercise plan. We can help you with that, if you'd like, but we will only make suggestions that are safe for your age and stage of development.
You have to base your diet on things you enjoy eating, or you won't stick with it. Likewise, you have to base your exercise on things you enjoy doing or you won't stick with it.