@Yuliya18 Yes, it was a host cancellation, not a guest cancellation. Therefore Airbnb blocks your calendar as punishment. As Emiel, says, talk to Airbnb and explain you didn't understand how the cancellations worked.
You have a flexible cancellation policy. That means guests can cancel up to 24 hours before check-in and receive a full refund. You should change that to at least moderate cancellation policy.
Also, I really suggest you work on your listing info. There is really no description of the place at all. "Clean, modern, new" isn't much of a description. I suggest you look at other listings to see how others present their places. There is nothing there about your interaction with guests. There is no information about the washer and dryer, which you have checked as an amenity "Free or for a fee". If guests have to pay for the laundry, you should mention that in the description. You have "Breakfast provided" checked- do you make breakfast for the guests, or do you leave breakfast food for them? You need to make all this clear.