Another argument for slide toppers. They prevent water from pooling on the top of the slide in a rain storm. Retracting the slide with water on it brings it right in with the slide.
As to what to do now, you are doing it. Suck up what water you can and run the AC to dehumidify. Repeat until dry as you don't want the floor to stay wet too long. The plywood is not marine grade and will start to delaminate if it stays wet for more than a few days.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW