When returning to Washington, DC from overseas, newcomers to the area will note that most stores accept credit cards. The machines for using your credit card in stores, restaurants, and gas stations will vary. Many stores require a free membership card to enjoy discounts. Many large supermarket chains have self-checkout stations.
Grocery stores include Giant , Safeway, Harris Teeter, Food Lion, Wegman's, Trader Joe's, Magruders, Whole Foods, and Shopper's Food and Pharmacy. Many have pharmacies. Safeway and Giant offer online shopping and home delivery. Ethnic grocery stores such as Lotte, Grand Mart, or Han Ah Reum may offer good produce and the cheapest prices on some items. Some stores have people who help load your groceries; you do not need to tip them. More ethnic grocery stores in Washington, DC area.
Discount "clubs" such as Costco and BJ's Wholesale Club require a paid membership to join, and offer items in bulk, as well as photo developing, pharmacies, car tires, electronics, eyeglasses, and more.
Alcohol is sold in separate liquor stores (except for beer and wine, which are sold in grocery stores in Virginia).
The two main hardware stores are Lowes and Home Depot. You can buy everything from nails and light bulbs to kitchen appliances and outdoor furniture and plants, as well as have keys cut (if you can't find one of the rare, old-fashioned local hardware stores).
If you are on a tight budget, you can buy just about anything secondhand. Used book stores, consignment stores (for clothing, toys, or household goods), thrift shops, flea markets, "antique" stores, and more offer bargains. or one can check Craig's List or Freecycle online.
Farmers Markets - these are held weekly in many neighborhoods.