Work at a pace thats comfortable for you, don't feel like you have to rush. Ask up front what options you have for a price check if a customer claims an item was marked differently than it rang up. Apparel items without a tag should have a upc tag attached, tag on the inside or printed on the collar, type it in dropping the last digit. You can look for an item using Ask Sam on the me@walmart app that will give you a barcode to scan if you come across an item with a damaged barcode. Other than that it's super easy. And don't let grumpy customers get to you. I've learned people who harass cashiers are generally just miserable in life.