Welcome!
I recommend the driver mod first. I'm a Gulfcoast Autocrossers member and we run in Lehigh Acres at the Buckingham airfield.
http://www.gulfcoastautocrossers.com/
Our next event is May 31st and June 1st and we even offer a novice school on Saturday that's included in the $25 cost. Loaner helmets are also available at no extra charge.
If you have never tracked your car, you will be shocked at how much untapped performance your car already has, as it sits right now.