Be a shop assistant
The Victorians were used to service.
One of the most well-respected jobs was a shop assistant.
You will need some sugar, some tea and some flour. You will also need brown paper bags and scales (NOT digital scales, spring ones).
Empty the foods into bowls.
Now one person can be a sales assistant and serve others, weighing out their needs and putting the goods into paper bags.
People will need to ask for goods in pounds and ounces. You will have to price your goods in pounds, shillings and pence. The pictures of shops in the videos give you some clues about prices.