Chin up and remain hopeful. I've made mistakes before and still gotten paid. And if you get called out for not following guidelines, it does not hurt to apologize/be polite. What helps me perform the shop correctly, is to re-read the guidelines before I arrive and also have a notepad on my phone that lists all the things I need to cover while on the shop. If I keep looking at my phone, it just looks like I'm txt'ing or reading email - no biggie.