What class should i be? on WoW?

Being a tank at max level in WoW can be rather difficult at times if you're new to it, but once you get better gear it gets a lot easier. Druids are good damage dealers and can heal, dps, and tank. It's a preference really of what you find more interesting and fun. You can also get help from other people on how to play each class. Researching is an amazing thing, i'll put a website in the source for you to learn about each class. Go to the forums on it and start reading.