I agree with all the advice people have given here on this thread.
Here's a few things I can re-emphasize from when I drove at the Ring last year in Spring and rented a prepped Renault Clio Sport:
•Do it!
•loved renting the car from and lodging at
https://www.rentracecar.de/en/. Super responsive people and easy process. Car had tons of grip and no brake fade.
•practice with Gran Tourismo until you've got the course memorized (took me an hour/day for a month). Use a quality racing wheel setup and it's important to really practice with the car you're going to be driving at in reality. Shift points and speed are important to note. Also practice in race mode where you get used to driving with other cars on the Ring. After doing all this simulated driving, I was super comfortable driving there in real life as fast I drove in the game.