Floydian is correct, Wii sports can't play online. It never had a wi-fi mode built into the game, after all.
We already have a hundred of these threads asking the same question, with the same answers. Please use the search bar in order to not create duplicate threads, it's spam and against the rules.
Reading a game's/the Wii's manual before posting an entire thread about it would suffice too. Also, please read the rules.