Take the SD card from your old Wii, put it in your computer and copy all the files to a temporary location (you'll have to set your file management program...
You can't hook them both up at the same time unless you buy a separate adapter. Try going to an electronics store, and asking the employees what they have.
It technically is not a rule, it just changes the game up a little bit so if you want to have different winners/losers, flip the board. You can also check...
Open the small flap on your Nintendo Wii console, and you should see a red button. Hold that down as well as the long grey button on the balance board....