I almost hate to be the guy to say this but I was once in your shoes. I weighed 210 at age 14, and honestly it's very difficult to go away. I am currently 24 and I weigh 274, but my doctor says I am actually a health person because most it is muscle and muscle weighs more than fat. Being a person that was once (and still is) in your shoes remember these important things.
1) Change doesn't happen over night. If you are serious about getting into shape (and not just for one con) you have to make changes. I play tennis, airsoft, and hike for fun I don't do it to lose weight. I eat carrots because I like them, and most importantly, I workout because I want to improve myself. So find activities that you like. Join a youth soccer or football league, buy a frisbee and play catch with family or a friend, bike riding and walking are great but can be boring so invite someone along.
2) What you eat is very important. I know that diets suck! I have hated them for years. So here's what I do. Good breakfast (cereal and fruit) a good lunch (sandwich and some veggies, no chips) and then have a nice dinner, usually whatever my family is having. Keep baby carrots, apples and bananas for snacks. A good Idea is to talk to your mom or dad, and try to get some healthy simple cookbooks. This way they know what your goals are, and I'm sure you can learn to cook a few for yourself. Heck they will probably start eating some of them with you, which is always a plus.
3) Make your changes as you are ready. I tried that crash course dieting and similar techniques. Not a fan... However to help myself get into shape I stopped drinking soda and started drinking juice, then eventually water. I got soda out, and then I started on replacing candies, with carrot sticks. Eventually I got rid of most of the worst items for you. I current project is to omit fast food, but I'm not much of a cooking person.
4) If you have a craving kill it. This is actually the hardest part, but prove very effective. If you have a desire, either don't think about it, or control it. Example, the other day I had a craving for chocolate I ignored it but it wouldn't go away. So I bought one of those 100 calorie packs of oeros, craving gone, and I put the rest away. It's difficult but once you learn to control your cravings you are set.
focus on your goal and I'm sure you will get there.