People who are still growing don’t have to do anything usually. If you grow several inches you can possibly carry your present weight. Generally with people through to the end of their growth cycle, simply sticking to a good diet will allow your body to settle on a healthy weight for you.
Give us some more information but don’t immediately think of losing weight, at the age of 15 you can take your time and study up on this.
Oops, I can’t believe I forgot to list my weight. I think it’s around 135-140, and my ideal weight could vary, because I could always be 135-140 because of muscle. I just want to get rid of fat.
Is that 135-140 kilos or pounds? If the former then you need to see a doctor. If the latter, I have to ask why you think you need to lose weight. 140 lbs is not overweight, especially if you’re exercising hard. Remember that muscle is heavier than fat. And a pound a week is quite a dramatic weight loss. Assuming you’re a guy then you’ve likely another growth spurt coming. Don’t worry about it.