If you have not read the returning player's guide, I recommend doing that.
https://www.bg-wiki.com/bg/Returning_to_Vana%27diel
Send me a tell and if I am free I will definitely help. Cerberus might be low in population, but for what it's worth I would never consider leaving Cerberus now that I have met so many great friends here. Asura might be well populated, but there is something to be said about walking up to an Ambuscade, and going in as soon as you sign up, or walking out to Abyssea and all the NMs are up for your picking (i.e. no wait, no competition).