Multiplayer (two people on 1 PC)

I want to make a game where i can drive one car with the ARROW keys and fy friend can control the other car with the WASD keys. I already know how to make two cameras on one screen (split screen). I am not very good at coding so help is needed!

You don’t need to do anything extraordinary for this. You probably have something scanning for if(Input.GetKeyDown(XXX)) // do stuff, so add additional logic blocks for the remaining keys and apply the desired effect (brake, gas, turn, whatever) to the proper transform.target.

where do I apply this code?