Congratulations on your purchase.
Welcome.
About the water filter...
You can do a search on. WATER FILTERS.
and find many threads. From complicated installs to simple frames Holding the filters on the ground.
Water filter thread with pictures
https://www.montanaowners.com/forums...t=Water+filter
If you want simple use a "whole house" filter system. Put a Camco inline water filter on your hose between the spicket and your pressure regulator. Then a whole house filter before it goes in the rig setup on the ground.
Camco RV Water Filter Stand - Keeps Water Filters Upright and Off the Ground (40772)
https://a.co/d/0p0b1rk
I got one of these so I can see the filters and keep an eye on them. I mounted it inside the basement.
iFilters Whole House Water Filter, 2 Stage, Removes Sediment, CTO, and More, Minimal Pressure Drop, City and Well Water
https://a.co/d/hSU7xsn