Finding your way in Meknes is not very hard. The Ville Nouvelle is built along the east bank of the Oued Boufekrane river. This is where most of the hotels are and the railway station. On the other side of the river is the rather compact Medina. The jewish quarter, the Mellah, is on the south west side of the Medina, most of the impressive Moulay Ismail monuments on the south east side.
Within the Medina everything is at walking distance. The Moulay Ismail monuments are quite big, so this involves some more walking. To get from the new to the old part of town you can take a cab. They’re not expensive and easily found.