No matter where you go in the world, to survive, you will need to eat food, sleep a little to refresh yourself and to get other essentials, you will need to shop. Travelling exposes you to new ways of doing the activities of life and provides insights on how other peoples of the world live and perhaps why they do what they do. Eating Everyone has to eat and drink to survive. People in other countries don't have as much fast food as Americans have and see eating as an important social function. Though the United States has exported McDonald's, Burger King, Kentucky Fried Chicken and the natives do make use of these eateries, you are travelling to experience the native foods of the countries you are visiting.
Many people have concerns about the water in other lands.
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.