I have a loooot of Wizard Coins and I have no idea what I'm supposed to do with them lol. Help, please?

Well, you can spend them at the Token Shop at the Fair Grounds when it stocks, or the Oracle Token Shop in the Sacred Lands. Or, you can sell them if you prefer. You can use them for vending machines too.

[Edit]And Blackheart Hollow at the Darkside if you see anything there, I believe.

Ooh, ok. Thanks! :D

VENDING MACHINES = WIN. Even if you don't get anything that you want out of them, sometimes you get some rare items that you can sell for a pretty penny in your shop (and if you don't have a shop, make one). That's how I've made half of my sP on Subeta, if not more.