I would think you've more than likely got a leak. That probably isn't what you want to hear, but the rubber wipers around the slide should take care of most of the rain water as you are opening or closing your slide. Was the slide completely closed while the camper was sitting in the driveway? If it wasn't, or if the slide is out of adjustment enough that only one side is pulling up flush when you close it or the top to bottom alignment is off, that could allow water intrusion. It could also be coming in around the windows (not likely, as new as yours is, unless they weren't sealed properly at the factory) or from around trim. Check all your caulking carefully and pay close attention to whether the slide is sealing all the way around when it is closed. Hopefully it will be an easy fix, but don't let it go very long at all or it may ruin your floor.
Mike in Tennessee
2007 Cruiser 30QB
2008 Ford F250 Lariat 4x4 6.4 Powerstroke
Valley 16K slider
Ride-Rite air bags