Hi :) as the person above said, all you need to do is exercise more often and eat healthier. You can eat healthier by eating what your parents give you: try to avoid packaged foods and sugary drinks. If you want to lose weight talk to a parent or doctor and see what they have to say. It's a good thing to get healthy, but it's important to remember that your body is just a package for your personality. You should take care of it, but try not to let it have an effect on the way you feel about yourself.
Be patient and safe :)
Keep yourself active, eat a little bit of everything and mainly cut off the sodas, if drink any. inteed of having orange or apple juice, eat a apple or a orange. When you are young, you don't need to go on a diet, just keep yourself active and eat moderate.