I have Minnie Winnie 25ft but these are really similar as there isn't much room for design ideas.
Under our bed are the water pump, fresh water tank, and a lot of water lines.
At the outside is our main storage with also goes under the bed but there is no access under the bed to this area.
The side window does open, but the back window is emergency access only and therefore has no reason for a screen. If your back window has the ability to open, I would first look for where the emergency access is. I don't believe it would be any where in the front half of the RV as that is where the doors are. If you don't have an access window, I would be kind of worried.