First thing, I want to welcome you to the forum! Most people here are very helpful and experienced, so you have found the right place. This is going to be hard for you since most your friends won't understand what your doing or be supportive. Also, your family may not be supportive. No worries, WE WILL ALL SUPPORT YOU! Anytime you need some encouragement or advice, get your butt on here. Come here daily if you need to and read all the forum posts you can. This will help you keep your focus and head in the game. In the past, I have tried to do what your doing, unsuccessfully. The support group I have found here in this forum is what has me succeeding this time.
OK, enough of that.
You are pretty young and you are still growing. Make sure that you focus on proper technique when lifting and that you don't do too much too quick. Be patient. This will happen for you if you stay focused and motivated, but not overnight.
READ THIS (very good info):
Advice for Teen Bodybuilders/Lifters
You need to concentrate on eating clean (no fast-food, no soda, no candy). Tell your parents what you are doing and that you need help. Since they most likely do all the shopping and most of the cooking, you will need to explain to the what you are doing and why. That you need to eat lots of proteins (chicken, fish, steak...), veggies (anything green is sooo good for you.), healthy carbs (brown rice, whole grain bread, sweet potatoes, Quaker rolled oats). Maybe they will even take a que from you and start to eat healthier themselves.
I found some more articles that you should read. This guy has tons of info and gave it away freely to us where he charges his clients thousandes of dollars for it. He got banned from here, but luckily, his info is still available.
Principles of Training - Must READ/KNOW...
Lifts You SHOULD Be Doing...
Something I wrote a long time ago about bodyparts and lifting.
Finally, while eating is paramount to your success, cardio is how you are going to burn off the body fat you have. If you hate running, that is just fine, don't do it. There are many different ways to do cardio. Swimming. Bike. Racquet Ball. Eliptical Trainer. Those are just a few off the top of my head. Try to do 30 minutes 3-4 times a week. Mix it up and have some fun with it. Take a good multi-vitamin daily and Fish Oil. Don't worry about taking any other supplements yet. Not even Creatine. Wait until you are experienced and a couple years older.
Good luck and write back often.