In your case as a new listing I think you are best to call AirBnB and plead ignorance, be prepared for a long wait, new host did not realise IB was on what it was and see if AirBnB will cancel.
@Lana33 if you made a change to reservation and your guest accepted that change then everything is OK and you will not have any consequences
But, if your guest doesn't accept the change and request you to cancel then you will be punished with 50$ fee, blocked dates, not being able to get superhost status for a year and in your reviews will appear message: host canceled the reservation. That is not good.
or.... if you know some other host near you, you can ask him if he has free apartment/room and if he has and your guest agree than you can relocate your guest and pay for his accomodation to your neighbour.
Wow. Thank you soooo so much for the help. I have noticed, my using the app to update does not sync properly if later that same day I log in on a laptop to go to the site. I have had some confusion and questions especially about financial responsibility.
I am greeting my first guests today - their stay is for 2 weeks.