All good advice above.
If this is in a campground, the owners of most campgrounds also typically provide winterizing for a small fee. Our CG charges $50 to close and $25 to open in spring. Most members take advantage of this service. I don't but I may be an idiot in this regard. Most RV mobile services and RV sellers that are local also do this kind of work. You do need to take some action as far as winterizing your RV.
We use our RV in the winter. After winterizing in fall, we use the toilet and bathroom sink, waste side only. Re-winterize both before we leave. Takes all of two minutes. Never turning back on the city water after we winterize until spring. Something else to consider. We visited our RV last February. I went to the local big box store in February to purchase some RV anti-freeze for the toilet and sink, waste side re-winterize. All the big box stores had put the RV anti-freeze back into storage as they were preparing for spring. This fall, I purchased a few extra gallons of anti-freeze to keep at the seasonal site for winter visits.
We use a Pirit Heated Hose that we like very much.
Amazon Link to Hose we use.
I think you need to think about mouse control too. We leave poison in proper containers both outside and inside. Stopping them outside seems more important to me then killing them once they get inside. Some of our neighbors have neglected to do this and have experienced huge cleaning issues in spring. We also have sprayed expanding foam around all pipes and openings.
On closing weekend we also clean our trailer on the inside / outside and treat the seals with 303 Aerospace Protectant spray.
Lastly, bugs. We spay around our camper before we leave, often, and never experience bug trouble but did when we first started. Asian beetles are a real fall problem in our part of the world. Each slide gets packed full of them after closing. We found that spraying some powerful bug control concentrate we found on Amazon helps a lot.