I'm sure a lot of you are going to disagree with me here, but I'd have to say that a newer car like a P5 or an MSP is a bad idea for a first car.
Get yourself something cheap like a 1990 626 or similar. If you get an older car you will spend a lot less up front, wont pay the higher insurance rates of a new car. and most importantly, when you crash your car (and you will get in an accident sometime), parts are readily available in junkyards and are inexpensive.
To boot, you will become more experienced in repairing your vehicle and maintaining your vehicle, as it will be slightly less reliable. I never wanted to use this phrase, but it builds character... seriously it does. It gives you a good reference point on life, and helps you learn to budget.
As for racing, you should spend some time driving; give yourself at least 2 or 3 years. Don't bother with drag strips; you'll find mostly the ricer crowd there. Spend some time with your local SCCA club and run some SOLO 2 races. AutoX will help you learn how to control your vehicle under the most extreme conditions and will help you become a better, more responsible driver.
Most over; don't be an idiot on the road; racing is for the track only. The price you will pay in increased insurance, fines, and guilt is just not worth it.
There's my 2 cents