Trixie, welcome to the forum, and best of luck on your first shop.
Do remember that if you absolutely totally screw up, contact your scheduler immediately and reschedule the shop! Don't cancel. Leave it up to the MSC to decide whether you can reshop the location. Some MSCs, it's just a matter of going to the website and requesting a reschedule date, but some MSCs, you have to e-mail or call the scheduler.
This is useful info if you're submitting the report and realize, "OMG, I didn't DO THAT!!", whether it's ordering the wrong food item, forgetting to take a photo, forgetting to check the restroom, or even just going before (or after) the correct time.
Or forgetting to get a receipt....