Hello @Judy117,
It looks like your problem is solved, or you found how to delete the setting.
When I view your listing the "Availability" section just says "1 night minimum stay".
Listings with 2 nights minimum for weekends will say "On Fridays and Saturdays the minimum stay is 2 nights."
I also tried a test booking for 1 night, Friday the 24th of March, and your calendar allowed it in that it automatically suggested a checkout on Saturday the 25th. If the minumim stay were 2 nights the calendar would suggest Sunday the 26th.
If a seasonal, weekend or date specific minimum stay is set you'll see it at the bottom of your calendar "Availability settings" window.
There'll be an associated bin icon that you can click to delete the setting.
Steve.