There is no 'pressure' to control how hard it brakes, either it brakes or it doesn't. You press the brake Key on the keyboard, or the space bar for the hand brake, and it brakes the car skidding to a halt.
I've gotten significantly better, but still not sure how my times stack up against pro racers. I'm still learning myself as I only recently experienced racing on a course with tons of hairpin turns designed by someone in a race crew.
You'll need to play around with how hard you brake on either. In my experience, precision turning requires you to first apply the pedal break and then the handbrake. With cars, you'll have very little control if you're using the handbrake exclusively. Every time I tap my space bar for the hand brake, either the rear spins out, or the car just skids sidways until it hits something or stops skidding.
