It depend on how seriously you want to do as a crafter. Carpentry is hardly used unless its for housing.

If you dont feel like leveling up a gatherer class then I suggest leatherworking. the mats you need can be gotten by killing off mobs and its a pretty good money maker since most gear needs leather/weaver.

But as other's said level most to 15 cross classes and it'll be very helpful if you have a high level gatherer