Water - open streetmap, ie OSMAND or Maps.Me on the phone, search "drinking water" + show on map. If you find a public fountain/tap that's not on the map, return the favour by adding it. At least in France if you ask someone for water they won't insist on you sharing a few vodkas with them and get very upset if you decline.
Food - as above, cooked food can be a rarity in rural areas, and limited hours. I tend to pick up bread, cheese and tomatoes/onion, again open street map, "convenience store" often includes hours in places like France.