My advice is eat a healthy breakfast, that will even help with making your brain more alert and healthy so it can learn more.
Don't skip lunch, eat a healhty lunch. Sandwiches, salads, fruits, etc.
Stay away from soda like Pepsi especially. Ick. That's packed with sugar and
calories.
Ask you parents to cook a healthy meal. Or if they don't want to cook healthy for some reason, at least eat about half the portion you would otherwise eat.
Join a
sports team at school. Or even just something like Flags for the marching band. I was a chubby kid, and I did flags in middle school and high school. And I lost a ton of weight doing it. Great exercise. Of course I gained it back later, but that's another story...
IMO, you're too young to be lifting
weights and exercise bike. Get out and do things like going for a hike or playing baseball or walk around the mall a few times. Just be more active and eat healthier. Not only will you start losing weight, but you'll be glowing from happiness.
Good luck.