Want to know what time does tesco close on good friday ? check it out guys! ;) Tesco store majority will open on Saturday from 8 AM to 10 PM, but for good Friday, they will be closed all day! but for small supermarket, most of the time they will be open! because Government regulation for most country are allowed for some store to open on restricted day trading! e.g Food, Drink, Petrols/gas station spare part cars, and etc! i.e basic needs.
If I were you I will buy more stuff before Good friday started, because most majority big store or supermarkets will be closed for the entire day! the reason simply because big store most of the times, have to many workers and also their family have to make gathering or something like that! so it's very normal for big store to closed on holidays! but for small store they are allowed to open for business!
But maybe for small region, that far away from city center, it could be open! but majority they are closed all day! but if you don't want to go to small supermarket in your area, why not try online supermarkets! I am sure they will be open all day! you just need to order some food or drink via online! and they will send everything that you need! :)