New to RVing

[Mabro56]

We bought a 2010 gulf Stream 25TSS. It's the right size for us at this time, once we have the Grand kids with us, it may be a different story. :) Everything we used works, don't know about the furnace yet. When we looked it over before we bought it, everything seemed to be in good shape, however, the first time we camped in it, I notice the floor was getting spongy by the entry door and into the bathroom by the stool, there is no visible water on the floor. I would appreciate suggestions on what to look for and I know I have a repair project in the near future. The next question is, on the back wall between the closet and bathroom there is the slide out switch and below that is three switches, one for inside light, the second is for the porch light, however I can't figure out what the third switch is for.
Thank you for any help on these issues

[Bike Dr]

The third switch could be for a step light or possible storage compartment lights. Leaks are the number one problem with any rv in my opinion. However most can be repaired without extensive renovation if caught early enough. And you use the correct materials for the job, like no silicone on roof repairs. Not sure of your particular model but good luck hope this gives a few ideas.