First you go to the Creative page and press this button
Than press top-down. (You can only make Platformer with a season ticket) Name your game.
First, press "Settings" and press Editing Settings. Now, press the settings like this. This will help you edit faster and more confortable. I explain some of the buttons The play button is to play solo the game you've created. The + button is to add stuff in your map. The eraser is to delete stuff. The button with 3 layers is the layer button and it will decide which is on the top. Find more info in here. https://docs.creative.gimkit.com/ I'll explain in the future.
It's making your own Don't Look Down
What kind of map would you make with the Platformer mode? I don't have that one, so I don't get to play around with it! ;)