Hello @Aya1553
Airbnb Help which @Emilia42 kindly sign posted you to, is good for all the basics around managing your Airbnb.
When as a host you go to cancel a booking, it does flag up what the penalties are and asks you at least once, and maybe twice whether you want to go ahead with the cancellation.
Airbnb of course takes host cancellation seriously as it impacts on the reputation of the company and of course the guest experience.
Why did you need to cancel four bookings at short notice? If it might be covered by Airbnb's Extenuating Circumstances policy it could be covered by that.