That Supra is junk, you don't want to buy a car someone has put all kinds of money into. It is probaly there speed car that they beat the heck out of it and you don't know what problems it has had or what they "patched" for a short period of time.
Your 13 - 14, you sound like me, I was looking at Corvettes at your age. It's cool, gives you a better idea of what is out there, the price you can expect to pay, all types of models through the years, any common problems. Then you get into a different car and you go nuts researching that. I must of spent years online around 8 hours a day at least (Im online now everyday of the week around 12 hours at least) though cars I liked and this and that. Look into turbos, superchargers, nos, how to fix this, how to fix that. Just learn alot so when you get a car you have the "basic" knowledge about the car you are hoping to get.
Keep looking, keep your eyes and mind open, don't get set on one thing, you never know what you may want years down the road and it is very very interesting and beneficial to look into all types of cars.
Have fun, I sure did.
P.S. One little funny story, one car I was DREAMING of getting wasa 1979 Corvette. After a whole lot of research I found the strongest engine made was the L-98, which was a really heavy V8 350 5.7liter with 225 HP. The car was heavy, the brakes stunk and all kinds of other things just added up to shy me away from that model. I would of got it if I had 10,000 to dump into it.
Now I have a 99 Camaro SS with the LS1 Vette motor in it.