Here is the information on joining RWA:
myRWA : Become a Member
Once you are a member, you may elect to join different levels of membership called PRO or PAN, but it's not mandatory. As a general member, you don't lose any benefits by not joining the sub-groups.
PRO is for writers who have submitted a romance manuscript to a publisher or agent, whether that manuscript was accepted or not.
PAN stands for Published Author Network, and is just what it says. For RWA members who are published in romance.
I can't say enough good things about RWA. I've belonged for years and it's well worth the yearly membership fee. I adore my local chapter. They are my friends, my beta readers, and some really cool people to hang out with once a month.
The educational opportunities, the yearly seminars, as well as the updated lists of publishers and agents who represent romance are invaluable. They were founded in 1980 by a group of published romance writers who felt an organization was needed to promote the genre and advocate for its authors.
Romance has been the number one selling genre, at least in the USA, for over 50 years now.