Go to your Behind The Scenes page and scroll towards the bottom. Click on "Image Licensing Program" and you'll be taken to a page that explains how it all works. From there you can also opt in or out of the program.
Generally speaking, you should offer either Royalty Free licenses OR Rights Managed licenses, but not both for a given image. (I mostly offer RF, but have a few RM instead).
As for pricing, I find most artists here use the "Getty" default pricing option, so that might be a good place to start when in doubt.