I stayed at a very nice (acceptable) hotel in Ghardia three years ago. At that time it was the best in the town. It was within walking distance of the small downtown area. The people there are very friendly. They were also completely redoing the market area in anticipation of the return of tourists. At one time Conde Nast magazine listed Ghardia as one of the top l0 exotic places to visit (about 15 years ago). I must go back and see what it looks like now.
Visit the town of Beni Izgen (you have to arrange tat the city gate to have a guided tour).
We visited a home of a Mzabite family. We had met two sisters on the plane and their brother was there to meet them and he arranged for someone to take us to the hotel.. Two days later we were guests at their house. My husband is Algerian, but me and a ladyfriend from France were welcomed like family. We also dragged along a young American guy we had met at our hotel and in true Algerian fashion, he too was welcomed. Needless to say, the couscous was one of the best I ever had. After we left the upstairs area where we had dined, as we went down the stairs dozens of other relatives had come just to say hello and goodbye to us.