Ride height is a fundemental setup adjustment and an easy way of tuning the overall grip and balance of the car.
The "rake" is the angle created by running the front end lower than the rear. This will put more weight over the front of the car and provide more turn in. Ride height affects the car in both pitch and roll so a small adjustment will affect the car around the entire track.
Suggested start point: 25 front / 27 rear
Front: 25 - 28mm
Rear: 26 - 29mm