I ran my 1st track day back in 2002 with NASA at VIR. Talk about SUPER DUPER fun. We got 3 sessions both days at about 20 minutes - which did NOT feel very long at all. Learned alot of my autocrossing skills helped. Late braking, apex, and stuff. But things at a track happen alot slower. Turning, shifting and such.

But also realize the risk is higher too compared to an autocross. You go off at an autocross and you may mow down some cones. You go off at a track and you could meet Mr. Concrete/Rubber Tire Wall = bad for car!