Older cybpunk here.
There are genuine humans everywhere. Despite what the corps want, you can't
switch that off. Some suppress it better than others, but I find it fun exposing it. I like to make them crack and laugh. At a point now where I can make most people cave in to down-to-earth interaction.
Here's some homework for socially anxious OP: throw some innocent banter in to the convo.
Realise that there is an actual person serving you, and it is just a job.
Maybe watch Fight Club and reset your perspective. Make it a game. Look for patterns.
Have some sympathy too: unless they're a business owner(and even then…), people working retail trully are not happy with their job/life. At some point, they likely had a mother/father telling them they could achieve anything…and now they have this.
Don't over think things. They're not programs. I live the life too, but honestly, don't go too far with it. It won't buy you anything in the long run.