I recommend googling "West Palm Beach Parks" to find the beach you want to go to. We spent a weekend there for a cheer competition and although I had looked at parks, we had about an hour to spare so I thought surely we could drive to the beach to spend that hour. It was too cold to swim, so we just wanted to walk the beach and take a couple pictures. Well, we got lost in the multi-million/billion dollar homes with private beaches. Finally we found a public beach alongside a road, so we got out there for a while. It wouldn't have been a beach I would have wanted to spend a day or half day at if it was warm enough to swim. The parks would be much better. Online it gives you a description of the beach and park and how much it is to enter. West Palm Beach is not a tourist beach... it seems like almost everything is private owned or zoned into a park. I have limited experience there so maybe others have a different opinion.
Maybe this website with their calendar of events may be useful.
http://wpb.org/Departments/Parks-Recreation/Overview
Here is an article of the 10 best beaches.
http://www.10best.com/destinations/florida/palm-beach-west-palm-beach/attractions/beaches/