@Kathleen-And-Richard0 In that case you should inform the guests that new hosts will take care of them (assuming the new owners have taken possession of the property) and if they are not comfortable with that, you will need to cancel since it is not the guest's fault.
You have now blocked your calendar to future reservations, correct? I recommend that you de-list your listing to block any further Inquiries or Reservation Requests. Once all the reservations have run their course, you will need to permanently cancel the listing.
Payment for the reservations would need to be figured out between you and the new owners.
In the meantime, the new owner should create their account and set up a new listing.