I'm doing my first beach backpacking trip soon and would love some advice. I've been on several backpacking trips in the woods before, mostly the Catskills, but this is my first time on the beach. I'd love some advice and tips from those more experienced than me.

I'll be hiking at least 5 miles on the sand, probably soft. Should I bring a beach wagon/cart instead of a backpack? Both?

I see tips elsewhere about longer tent stakes, so I'm gonna be shopping for those.

I'm stuck on how much water to bring - there's no fresh water so I'll need to bring everything I drink.

Also fun things to do - for example with the lack of tree cover I'll be bringing my girlfriend's camera setup and see what kind of cool picture I can get of the stars.