Games like World of Warcraft that are free?

Well WoW is a MMORGP (Multi Media Online Role Playing Game) so you would want to search for games such as that. I've played a Japanese one that is like it in the way that you go on quests, and travel the world battling monsters and it's called "Onigiri."

Or you could try some of the other games from the same makers of WoW (i never actually did though so I don't know exactly what they are like)

Those would include: Diablo, Starcraft, Hearthstone, or else just some WoW add ons if you wish. Have fun gamming.