When you get there, you will meet both Whis and Beerus who will inform you that you are going to be trained here. You can bring any buffs from food with you, so you might want to eat before traveling.
Head on down to Add-ons and select the first DLC and you will be warped there. To do that, enter the game and go into the start menu. In order to get Super Saiyan God mode, you must first access the DLC.
