I recommend checking out the Mead Hall if you’re interested in Alliance RP. Right now the Mead Hall is currently campaigning against the Scourge on Azeroth.
You don’t HAVE to be a Dwarf because they let my stinky Draenei hang out. You also don’t have to join any guilds to hang out with the community too. I’m on a break from Retail right now but generally this is my main activity hub for RP.
Otherwise Alliance RP is a little quieter compared to Horde on WRA but check the times that you are playing. Peak server times is usually around 16:00-18:00 server time but the few times I go look for walk up I don’t have too much trouble finding RP.
Duskwood also has some activity but I’ve yet to drag any of my characters out there but Thomasbates can give you more details on that.