Hi,
you are supposed to use the jingjing.xu replacement for the tutorial. You overwrite the name of jingjing.xu account with your name and therefore you change the person name. But the USER stands for your login details and means the user and password you need to log in. Person and user are two different things. Person is the name in the erp5 system while user is for your login details.
I hope this helps to reduce your confusion.
Best regards