Hi, Scott!
I am excited for you! Staying at Port Orleans Riverside is so much fun - you may never want to leave your resort!
With kids, I am guessing your decision is going to be made for you. Once they see the pool area and fun water slide at Ol' Man Island, they are going to be set for the day! There is a nice food court, so I suggest grabbing lunch, sitting pool side and enjoying the day.
Other activities your group might enjoy:
-Take the boat to Downtown Disney for lunch and shopping
-Walk down to sister resort French Quarter to get some Beignets from their bakery
-Catch and Release fishing at Ol' Man Island
-Click
HERE for even more resort activities!
Whatever you decide, enjoy your first magical day in Walt Disney World!