ACC Driver trying out GT7

I like to simrace as much as I can, it’s a passionate hobby of mine and I enjoy the simulation/simcade side of it all. With only a PS, the two most viable games (from what I’ve learned) are ACC and GT7. I’ve raced ACC for about 2+ years now, and jus decided to pick up GT7 bc of a sale. Anything I should know? Similarities and differences? Competitiveness & cleanliness? I’m very interested in competitive driving. Anything helps at all, from simple tips to elaborate suggestions!