A) To play two player split screen on Xbox, please do as follows:

1) Ensure that both controllers are recognised by the console and that the Xbox symbol light is lit on both (Series S and X users may have to plug the second controller into the front USB port). You will need to have at least two users (gamertags) created on your console and a controller assigned to each.
2) Once in the game press the View button on the second controller and choose the gamertag (which must be different from player one). You should see a message saying the a player has joined the game.
3) Go to the arcade option of the game. If Time Trial is greyed out then the game has registered that there are two players wishing to play. If it is not greyed out repeat step 2)
4) Choose freeplay, setup the options you want for the game and then start the game. You should have two player mode enabled.

B) The instructions for PS4/PS5 are very similar except that you will need to ensure that your console is connected online, as the split-screen mode does not work if the console is offline.