Turn up any time in the two hour period, quote the name the order is in and bung it in your car. It's already paid for. You used to have to transfer the stuff from trays to your own bags (or chuck it in loose), but now I believe they're bagging it up.

I regularly used this service when the missus was incapacitated, as I couldn't bear shopping. You're lucky to get a slot, I understand they're as rare as hen's teeth at the moment, although I believe they're giving priority to the vulnerable.

Used Tesco C&C for the first time last week. I didn't know how the system worked either. 6-8pm slot so thought I'd turn up about 19:30. Collection point was next to petrol station and under a canopy. Pulled up and immediately told to stay in the car until my shopping was ready. Chap left the crates at the back of the car and walked away telling me I could now get out. Shopping was in bags for life as presumably the old thin bags have all gone (to landfill ;))

All very straightforward and no queue. Chap said they have 24 slots an hour and 20 of them turned up in the first 40 minutes. Wasn't surprised and was why I left it until later.

HTH

Very easy process. My slot was 8.00 - 10.00. Turned up at 7.55, was only one waiting apart from car being loaded. Within 30 seconds another car turned up. Car in slot left couple of minutes after 8. When I departed there were 5 cars in queue. Groceries already bagged.Placed in crate for me to load. Staff of course kept distance.

Will reuse bags, currently sitting in bucket of bleach, disinfectant and soap. In due course going on washing line in garden for at least 24 hours. Virus hates being outside, even more so in sun light.