Type of bags to bring as a mom?

Does the Destiny ship have towels, water and bathrooms readily available around the kid water/pool areas? Or do we have to bring on our own from the rooms before heading there?

I will be staying in deck 2 so it’ll be a long journey up to the entertainment top. Originally only wanted to have a fanny pack for important items but now wondering if I should pack a humongous beach bag to carry around within the ship (towels, sunscreen, snacks, waterbottles, wet wipes, etc…). Same with when leaving for Castaway Cay & Lookout Cay?

Thanks