I use Tesco ocasionally when the weather is bad or I can't be bothered. I would prefer to see the fresh meat, fruit & veg before buying, but I have never had any problems.
Without committing yourself to an order you can go to their website and see how to book a delivery, negotiate the lists, tell them whether to substitute the nearest thing for anything out of stock, etc.
If the order is over £40, delivery is from £2.50 to £5.50, if it is less than that another £4 is added on as well. It is very easy to get to £40! You can add more things to your order or delete things, up to 11.45 pm the night before it arrives.
They deliver either in bags or in a crate, which is carried into your kitchen and emptied out for you. Any chilled things are in a cold store in the van, and any frozen stuff in a freezer, so everything stays fresh. If a substitution costs more than what you ordered, you don't pay any extra, and you can reject anything which is not exactly as you want. If you wish you can look at previous orders to remind yourself of stuff you might need again.
Another shop I sometimes use is Iceland - you can shop in person and they will deliver free the stuff you have bought if it is over (I think) £25