What level do you have to be to get a pet on wow

Well for combat pets you start with one then can tame more at level 10 (for hunters) or for warlocks you can get a pet at level one. Shaman can get spirit wolves at level 60 if they are enhancement. Deathknight can get a pet at level 56.
If you want a Non-combat pet though you get buy one eather at the AH or by different venders. One vender is in elwynn forest, south of northshire valley
http://thottbot.com/c6367, but there are plenty others throughot Azeroth