France closes on Sunday and Monday, including Petit Casinos (I don't think there is one in SJPdP). In a pilgrim town like SJPdP something will be open, but expect a late opening, 9 a.m. or later, and expect them to be closed Sunday afternoon. You will do best to shop before the Saturday closing, usually about 7 p.m. Huntto serves breakfast, but I don't think it does so for walk-by traffic. You can get lunch. Orisson has a bar, so it will have food.