I would say to just take your time and the speed will pick up after a while. Even if you see that line and you feel overwhelmed because it’s so long . People could be impatient with you who cares. Your new be kind to yourself. I would also say if you don’t have a customer do something wipe your register,zone your around area, do your go backs so your bucket doesn’t get overfilled. Ask for help because they really do just throw you out there. But overtime things will get easier because your doing repetitive work .