Do this first
Street Survival School, sponsored by Tirerack, BMW Car Club of America, Sports Car Club of America (SCCA)
This school will teach you about the limits of your car and your own limits, with an experienced instructor in the car. Then as others have said, Autocross, aka solo racing. Develop your capabilities as a driver. You may think you are the greatest driver in the world, and you may be, I don't know. But it's often the other morons on the road that will kill you.
One day, inexpensive, fun, and you use your own car. It will be the best $75.00 ever spent. Your parents may even pay for it.
Learn your car then modify.
Welcome to the forum. Hang out, yack, don't get yourself dead eh?