For most countries in northern and western Europe and other developed countries, tap water is safe to drink, though it may taste differently from what you are accustomed to at home. If you have qualms about the water in a particular area, do as the locals do, buy bottled water and do not ask for ice in your beverages. You can also boil your water, carry iodine tablets, or even take a portable water filter if you are staying in a less developed area for an extended period of time. Use bottled or canned fruit juices and other non-alcoholic beverages to supplement your liquids. To eat cheaply, go to local bakeries, grocery stores and outdoor markets and buy food that appeals to you.
Many hostels have communal kitchens supplied with pots and pans to cook a reasonable meal.
Supermarkets are also becoming common in Europe, with prepared meals available for purchase. Another interesting spot to go food shopping are the department stores, usually with a food department in the basement of the store. Should you want someone else to do the cooking, check the lighter meals that are provided by cafes, pubs, bistros, tapas, brasseries, winstubes, tabernas, etc. Restaurants serve more substantial meals, usually a multi-course affair with soup, main dish, salad and dessert. Menus will often be posted outside the restaurant with a price list, so you know in advance how much you will pay.