What experience do you have?
If you have NO experience, getting started in autocross is a great thing to do. You'll learn all the basic car control that you can't easily learn on the track. (the overdriving mistakes that you can freely make at an autocross can often be very expensive on the track) Drivers with an autocross background usually make very good road racers.
Once you've got car control down, do a couple track events with any one of the clubs that do track events. And if "you got it", getting a license to go racing with NASA or SCCA should not be difficult.