In all honesty, if you want to get in a guild you should go Alliance. Horde guilds are a tough nut to crack even with lots and lots of experience. A guild really want s not required though unless you want to get in on the 10v10 action.
You can always populate your RealID with Twinks. We have several lists. Many people run in multiple brackets so you may want to add people from the 10-19 and look to see who is posting here and in that we brackets as well. Such as the Level Twenty and 20-29 sections.
Good luck and have fun!!