Heya! And welcome!
First, maybe a sticky regarding such questions would be a good thing, and the positive news for you, friend, is that aside of established rpers being on the server, lots of new people have asked the same questions before, and recently. So that covers ‘yes, people are flocking to the server for rp every day’.
There’s most probably not as much and as visible rp as on Argent Dawn yet, which is owed to the server being young compared to AD which had years to establish itself.
On alliance side I know that Southshore is a hub (many rp guilds on the server are located in Lordaeron, such as the scarlet guilds, Southshore, the Frostwolf Legion, Tarren Mill etc), as is Stormwind (cathedral square?) and as is Ironforge (there’s an rp tavern there that I know of). Tarren Mill and Brill are also suggested for hubs from the forsaken players, and Orgrimmar has seen some rp from my guild and others so far. That should also answer the question about smaller/racial hubs, it’s really not ‘there’s that hub and everybody is there’, things are being established still.
I’ve not heard any rp guilds complain about membership numbers yet except for, pity, the guild Elwynn Forest having officially closed down recently. I know that my guild, the Frostwolf Legion, has had a steady influx of new members lately, can’t say much about other Horde guilds, but I’ve heard of several alliance guilds being well frequented. Some are smaller still and some are bigger already, again everything subjective and also the server is young and things are taking their time to develop and grow.
I’d say looking for rp on this server is a save bet, there’s rp everywhere, and rpers, but you have to look a bit closer to find them right now. During questing, in cities, flag profiles are a sure bet and otherwise just try rping and wait for responses. There’s been events organised yet, there’s regular taverns that opened up shop, etc. But we need to be patient about that grand vision of a lively server rp community, it’s in the making.