Are you trying to ask what the pay period is? That is up to the employer. And no, it's not Friday to Friday. If you are paid weekly and the pay period starts on Friday, the pay period is Friday to Thursday. There is only one Friday in each week.
"I was taught that if a place is open 7 days a week payroll ends Sunday... right?" The pay period COULD be Monday to Sunday, but as I said, that is up to the employer.
"I work weekends and I’m wondering how that would be put it my pay" What do you mean? This is very straightforward. If the pay period starts on Friday, you will be paid for Friday, Saturday, Sunday, Monday, Tuesday, Wednesday and Thursday in each pay period. If the pay period starts on Mondays, you will be paid for Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday in each pay period.