Do it. Just use street tires. Do not push to the limits. If you are in a group with modern Porsches, you will be the slowest one on track. Don't let ego make your decisions, relax and have fun, don't even worry about lap times.
I did Barber Motorsports and Talladega this summer. Barber is beautiful, and I had the only air cooled car in a field of 165 cars. Talladega was a follow the leader, no passing, but I was cruising along at 125 MPH, AC on, and my wife in the passenger seat on the 33 degree banking.
Get yourself an instructor. Likely they will require you to have one and they will put you in the beginner group. If the instructor tells you to hit the curbs too shave a little time, ignore that advice. No reason to abuse your suspension to gain a 1/10 of a second.
Most important, have fun!