Where to Fish in Galveston?

New to fishing so please forgive me for asking so many questions. I've only ever been to surfside jetty, texas dike, and sea wolf park. I don't really like texas dike as much as the other two but I was wondering if anyone had any other good spots to fish? I'm trying to target some flounder during this season and was wondering if anyone knew any good flounder spots or even mangrove snapper. Also I mostly use live shrimp but what are some good baits for flounder? I don't have a boat or a kayak but I don't mind a small hike. If anyone has any info please let me know!

P.S. I know some people don't like to give out their spots but any recommendations would be appreciate.