That's a good question and you'll get a lot of different answers on this great site!
If possible, try to test as many different bows as possible, just be sure to get a bow that isn't too heavy because you will not be able to shoot it as well and it can be quite frustrating for a beginner.
First of all try to determine your actual draw length. If you have a yardstick around the house, you can place one end at your breast plate and stretch your arms out and see where your finger tips hit towards the other end. This will give you a pretty good idea of your draw length. Secondly, you want to match the proper arrows for your bow weight and draw.
Most production bows are rated at a 28" draw, but at your age and depending on your physical attributes, you may be several inches shorter/longer.
Maybe try to try out some bows in the 35-40# range at your draw to start and you can always work you way up a bit later, once you learn correct form and are hitting your target well.
This is a great place to find out about all the great things that Traditional Archery can bring to you. You'll find many fine archers here that will address your questions and help you on your journey.
Don't get too concerned with which brand, there are lots of nice older bows and some attractively priced newer bows that will be great and won't be too expensive.
Finally, I would like to send you a couple of items which you can keep if you like. One is a great book by Sam Fadala called "Traditional Archery" and the other is a really cool DVD called "Beyond Adrenaline" which captures some great traditional hunts.
Please ask your parents to contact me with your information and I'll send these out in time for Christmas!
Welcome aboard Adam!