This is two questions, disguised as one 😊
1. In setup.ini, almost any setup adjustments can be coded in, to offer these adjustments in-game before driving the car. Probably easiest to look at examples which DO offer those adjustments.
2. Saving that adjusted setup, I've seem people say it's possible to save it with a specific name to make it the default. I've seen it referenced in this forum, but can't remember exactly what it is, most likely "default"

or somesuch.
PS. Not at my gaming PC rn, else I'd post examples. Sorry.