Welcome to the forum. It sounds like you have the mechanical portion of the RV under control.
I think the 360 is a solid engine and will be reliable but, maybe a little thirsty. RV's are not economy cars.
I don't know anything about the Odessa. Most RV's are basically the same.
The big thing is check for leaks. If it has a rubber roof it will probably need caulked and possibly coated. Not a difficult job.
A small leak can cause a lot of damage if it is not stopped/repaird quickly.
Tires are a big concern on RV's. They usually age out before they wear out. If it's been sitting for years it may need new tires. Many replace their tires at 6-10 years.
You can google the appliances and find manuals for most models.
Don't hesitate to ask questions on the forum. Someone will have an answer.
Keep us updated on your purchase.
You daughters will love RV traveling. :C