I´m working in HHN, though not employed by RYR, and living in a nearby village. Accomodation is not a problem. Many cabin crew live in Lautzenhausen, which is just a few minutes walking distance from the terminal.
As it was mentionewd before, you´d better bring your car (You can make it in a one day drive if you really go for it, or make a stopover in northern Italy or Switzerland for one night. I know one male cabin crew member, who regularly drove his old Landrover from Portugal to HHN), since then you´ll have a much wider choice for accomodation (e.g. along the Moselle valley) and shopping. E.g. I live about 25 km away, which takes me about 20 minutes to drive.
I wouldn´t recommend moving to LUX or Trier (Trevere), since there can be traffic congestion on the road and rents in LUX are not exactly cheap (accomodation around HHN is quite cheap and there are many empty houses available, though, due to bad past experience, some landlords refuse to rent to RYR cabin crew).
General shopping (Groceries) is available in two supermarkets in Büchenbeuren or Sohren, about 5 km away from the airport.
The next towns with a series of shops are Simmern (20km), Kastellaun (20km) and Morbach (10 km) from the airport.
The next city is Koblenz at the river Rhine with department stores, boutiques etc., about 1 hr drive from HHN airport.
Then there are Mainz, Wiesbaden, Cologne and Frankfurt, between 1 and 1.5 hours drive away from HHN.