Too late to go to a driving school for a cdl, just memorize the alsaps (air break test) ALSAPS = 1. Air leakage, 2. Low air alarm/buzzer 3. Spring brake (pop up), 4. Air compressor, 5. Parking brake (same as spring brakes, but different use here), and 6. Service brakes. There’s a video in YouTube by some guy in Eastchester that shows you everything very detailed. Memorize every step and you will be good .. Good luck