So you patched your Mario Kart Wii game with the Mario Kart Wii Wiimmfi patch? If not, you can download it here (https://wiiki.wii-homebrew.com/Wiimmfi_(en)/Patcher). If you did patch it and you tried to connect online then yes you have to wait a week before you can play. To see how much time you have left until you can play, try connecting online and it will give you am error code. Compare that error code to the codes here (https://wiimmfi.de/error) and it will tell you how much longer you have to wait.