If you are a minor, fasting is not appropriate for you. If you can, speak to a doctor about your weight and what you can do. If not, maybe a health teacher or nurse at your school. And then, if not, your mom - not that your mom isn’t a good choice, I just assume she knows less than the latter categories.
Only kind of fasting that’s really appropriate for a minor is daily intermittent fasting. You still get your calories/nutrients for the day but you benefit from not eating throughout the entire day. You could skip lunch and still benefit but you still are eating breakfast and dinner. Lots of kids skip lunch because they just aren’t hungry and are totally fine because they just don’t need to eat so much.
Speak to a doctor about it and see if it’s OK for your current life stage.
Avoid fasting until you’re fully grown. When you’re young, you should enjoy life.
One thing I would reccomend before you jump on fasting is to switch to lower carb, that is cut out the sugary junk foods and processed foods. Doing that now will build a solid foundation for you for later. Also look into intermittent fasting of 12 hours, or 10 hours. But again, go speak to a doctor about it with your mom.
If you are still growing, fasting can permanently stunt your growth.
What you can do instead is focus on recomp. While you have an abundance of growth hormone - turn that extra weight into muscle. Your future self will say a big thank you.