[F]What is the best way to paint a fiberglass tub and shower surroundings? I know there are preparation steps that have to be done, but don't know any specifics.

Questions about painting fiberglass tubs and/or showers have been asked and answered previously on this site. I did find one link to a thread here where you might find information that is helpful to you. https://www.askmehelpdesk.com/plumbing/resurface-fiberglass-tub-shower-1-piece-shell-41505.html Also, if you look down at the bottom of this page, you will also find questions about similar topics. You might want to click on them and see what the answers have been.