Indicate whether the night price is the 'total price' or a 'from price'.
For a 'total price' you enter the nightly price that applies to your accommodation per night, regardless of the number of guests. You enter the maximum number of guests that can stay in your accommodation on the booking tab.
At the 'starting price for a number of guests' you fill in the nightly price that applies to your accommodation per night for a fixed number of guests (minimum 2). At the booking tab you can indicate how many guests are included in the starting price and add a price that applies to each additional guest.