@Michelle568
It seems that the first inquiry was a "booking inquiry" and the second one was a "reservation request".
https://www.airbnb.com/help/article/838/what-is-a-pre-approval
https://www.airbnb.com/help/article/85/how-do-i-submit-a-reservation-request
https://www.airbnb.com/help/article/75/how-much-time-does-a-host-have-to-respond-to-my-reservation-r...
https://www.airbnb.com/help/article/360/can-i-decline-booking-inquires-or-reservation-requests
When you cancel a confirmed booking, the dates stay blocked so that someone else cannot book - from what I understand, this is basically to prevent hosts from recieving a reservation and then cancelling if they are able to get bookings at a higher price later. Airbnb MIGHT unblock those dates for you if you contact them and explain the situation.
Whatever you do, NEVER cancel a reservation. Even if it's a mistake! If you absolutely have to cancel, then make sure your reason meets the condition to avoid penalties for cancelling, and then contact Airbnb and have them cancel for you.