In the UK supermarkets sell groceries mainly, not white goods. Some larger supermarkets such as ASDA sell some small electronic goods, like phones, TV’s, microwave ovens, and other gadgets, and clothing, but not large white goods like cookers/fridges/freezers/washing machines.
For that you’d need to go somewhere like Currys PC World, Argos, John Lewis. Those stores don’t sell groceries, and are not supermarkets. Tesco sells white goods online, but not in their supermarkets.