Towards the end of Covid, I made the decision to give up my car (insurance at 80 years so high, and lots of public transport local to where I live).
I then commenced shopping on line with my normal supermarket = Sainsbury. My eldest daughter purchased a shopping voucher enabling me to have one hour choice of delivery.
Main problem I had with this was that the minimum amount of the shop had to be £40. Living by myself, always cooking from scratch, this was impossible for me - my normal full weekly food, and cleaning shop was around £33-£34. I used o add in books of stamps, box of chocs (for xmas), etc but even with those could still only make that forty pounds three out of four weeks, so once a month I would go to my nearby very large Tesco for a small shop.
Still keep this shopping pattern, and have cut out certain food items which I felt were not really necessary, even so, just putting in my weekly staples, soon takes me over that forty pounds. This last weekend, I did my Tesco monthly shop - noticed that their own butter (which I can easily remember same price as Sainsbury's own was 89p was now £2.00.