you need controllers! Playstation controllers aren’t supported by windows computers because of the rivalry between Microsoft and Sony. You can make them work with a 3rd party app though
im not sure which controllers all work, but the easiest way is xbox controllers for windows computers and playstation controllers for apple computers.
i can add some functionality for a second player on keyboard perhaps, but i’m afraid it’ll be hard to play the game that way!
another way to play together is through Steam Remote Play Together btw