Yes we have loaners. 90 is still OK for autocross I believe.
Don't worry about tires. Come out and burn up the ASXs or whatever is on whatever wheels, and if yo ulike it, then decide. You will learn a lot faster on less sticky tires because they have better feedback, both audible, and tactile.
The worst thing you can do as a newbie driver is buy a set of Hoosiers.
Come out and have fun on whatever.
Oh, and occasionally, we are more pediatric than pedantic...
