Nostalrius Begins - Quality wow vanilla realm (1.12)

how long does it take to get av exalted and what do u do? do u farm the quests or kill other players or win? because all the games i join is the ally's holding off the horde at the bridge for 6 hours

Fast winning is the fastest rep. Next in line is fast losing, then average length (under 2 max 3 hours) winning, then a solid turtle with lots of people turning in repeatable quests, then a mindless turtle.
You'll generally get a mindless turtle in most games since the people with any clue whatsoever usually get done with their AV rep and never come back to the shithole. It's much better during AV weekends (bigger amount of rep oriented players in game, also they sometimes can play, too).

if all you care about is rep then no point in doing AV untill AV weekend, at least as alliance.