Welcome ot BNB, maybe I can be of assistance. You can choose any car that is under $25,000 because that's how much you start out with. Each week, you get a weekly pay day of $6,000 to spend on your car in any way you want. Whatever class that car is, you would use that list for prices on parts. For example, you buy a Corolla AE86. That's a D class car, so you would go into the "How to Get Started" thread and scroll down to the D class list and go from there. You can also buy parts from other people in the parts classifieds if you want. That goes for cars too.
Let me know if you have any questions!
-Impulse