Just bought my first RV, Serro Scotty Dodge Dakota

I can't help much as I'm also new to this, but we just got a 1994 Four Winds that had 11-year-old tires. We found two labels inside the driver's door that had factory specs; one from Ford for the chassis, including original tire size and recommended inflation rate, and a second from Four Winds with RV-type info such as GVWR, etc. We got 7 new tires (don't forget your spare!) in the original tire size, but went up one rating for weight from a D to an E.