Hmm, hard to say because I mostly do it intuitively, also inherited some of it from playing FM7 which is less forgiving. Most important thing is getting a good angle and then controlling the throttle to keep it there. There’s probably some decent videos about it on youtube. It’s hard! Just takes a lot of practice.
I can kind of recommend doing your own tuning though. If you download one you can’t adjust anything to preference at all. I’m also definitely an amateur, still don’t really know what I’m doing, but I think it helps you get a better grip on the car you use. My most stable car right now is my '93 Nissan Skyline GTR, the Nissan 240SX is also very good, both with the rocket bunny widebody kits.
As for tuning, just go for a reasonably powerful engine, don’t need to go overboard with it, you can always add more if you need it. My Skyline is only tuned to A800, not super powerful but the most consistent car I have right now. I’m still figuring it out myself, getting the gearing set up right is still mystifying to me. Most important is differential to 100, tire pressure to whatever works for you (lower for very powerful car, higher for weak car etc.). I also think stiffening the rear of the car works well.
You can probably just look up a build on youtube and copy that to start with and go from there.