It comes with red, yellow and white connectors as standard - do you have sockets like that on the TV? Or a SCART socket cable is also available, I think. If you don't have either of those on the TV, do you have a video player with them, as you can sometimes go through one of those.
Ours has three individual small round plugs (red,yellow & white) which going into a scart adapter which plugs into the (flatscreen modern) TV. Pretty sure our old TV could take the small round plugs. HTH
So you have the Wii? I think you do have to tune the TV to it - our (newer) one can do that automatically. There should be something in the instructions to get a menu page up so you'll know it when you find it. IIRC