@Elaine772 If you are unsure about a host, rent from an experienced host, not from someone with no reviews or who is a new host. Be sure to know what their cancellation policy is as well. AirBnB is paid by you when you booked, but does not pay the host until after your arrival.
If you do arrive at a property at the arrival date and time and are unable to check-in for whatever reason, contact AirBnB, make your complaint and ask to cancel if the host is unreachable or not responding. You may be refunded (or not) per the terms of the cancellation policy, rehoused, or refunded in full by CS.