Hi Andrew and Welcome to the forum!!
The storage under the bed usually has carpet (mine does) and we usually keep some toys for the grandkids and our camping chairs stored under the bed. With the space carpeted, items don't slide around much at all.
The outside stoage space is where I store my level blocks, plastic totes with electrical, sewer, water hoses and other items such as a small tool box.
I placed carpet in my outside storage compartment to keep it cleaner and to help the items remain in place as much as possible.