After going through a tunnel from your spaceship to station "Tacoma", you'll find yourself in the main hub area from which you can travel to all other areas/modules in the game.
Right in front of you there is gonna be Engineering entrance, then Cryogenics capsules and then the entrance to a Biomedical module. Basketball "arena" gonna be exactly where the Biomedical entrance is.
Opposite from Biomedical entrance you'll see "3-point line" switch. Turn it on and you'll see holographic spheres around basketball hoops.
Just take a ball (gonna float around in this area) and throw it while being outside of the holographic sphere. It's easier to do while being above a hoop.