for p1 its arrow keys. for p2 its wasd. for p3 its yghj. to change car skin: p1 is 9 key p2 is 1 key. p3 is 5 key. to change track its space bar. if you dont wanna play p2 or p3 then dont control them. the cars are auto drive. just click whatever key is go for you and it will go. if you get stuck click that key again until you start moving again.
i made it from "20 games to create on scratch" book. then i made the project "drive me crazy". then i made it better. enjoy :)