In the main menu, you can change which buttons map to which actions. So make your changes there then press whatever keys you mapped to: up, up, down, down, left, right, left, right, turbo, turbo, turbo
You can add them to tours or worlds to play them. Or you can enter the secret code (found by players in beta 1) on the game type menu: up, up, down, down, left, right, left, right, turbo, turbo, turbo and that will unlock the minigames game type option.
By "turbo", do you mean "right control button, and always right control button"? Because I use a laptop that doesn't have a right control button.