Instead check out some tutorials on how to move stuff with Physics2D (with Rigidbody2D).
This will let you trivially put colliders on the player and walls.
The above code must change when you go to physics.
With Physics (or Physics2D), never manipulate the Transform directly. If you manipulate the Transform directly, you are bypassing the physics system and you can reasonably expect glitching and missed collisions and other physics mayhem.
Always use the .MovePosition() and .MoveRotation() methods on the Rigidbody (or Rigidbody2D) instance in order to move or rotate things. Doing this keeps the physics system informed about what is going on.
With a wheel collider, use the motor or brake torque to effect motion.