Nice looking rig!
IF going FT you need to 'start' DIY as much as possible.
Winterizing it yourself would be a good starting point to learning plumbing system
12V Side of life is good reading
The 12volt Side of Life (Part 1)
RV Electric more good info
RV Electric
Go thru rig with pen/paper and write down each component BRAND/MODEL
(water pump, water heater, A/C Unit--thermostat, fridge, converter, inverter, power supply etc)
Then goggle each one for 'Service Manual' (Atwood GC6A-3E Service Manual....example of water heater)
Then download/print and place in 3 ring binder.
You will then have YOUR own specific owners manuals for your rigs equipment.
With that info you can DIY/Learn to DIY cause as a FTr it comes in real handy (and cheaper)
Good luck!