They should teach kids about puberty in school. This is the third question in regards to this subject.
If you do a little research into puberty, you will discover that you might eat like a horse because you're going through a growth spurt. Your face will begin to slim down in your later teens. Walking at least 30 minutes every day will help you feel better, especially during your menstrual cycle, and will help you be active. Your weight is fine and nothing to stress over.
Remember to eat fruits and veggies more than you eat junk food. Hydrate your body with water. Cut down on pop. You've got several more years of puberty to go through so no need to worry yet about your weight.