The first thing to do in terms of purchasing your own race car is to determine the CASC-OR race group that you plan to participate in.
Pirelli Super Touring Sprints (cars running under 1m31s at CTMP)
Pirelli Grand Touring Sprints (cars running over 1m31s at CTMP)
Formula Libre, including Formula Prototype Challenge and F4
Toyo Tires Formula 1600 Championship
VARAC Vintage/Historic (Production-based and sports cars built pre-1980)