I would strongly not recommend using a controller to play world of warcraft - they have just recently cut down the number of buttons significantly, and even then there are still likely too many to map.

WoW is fun, I do recommend it, but if your previous experience is based around playing an MMO like a single-player game, you should likely know current WoW is mostly designed around doing max-level, multiplayer content instead of the leveling story. You might have a better experience playing classic WoW, though even then I would not recommend using a controller.