To send new booking and cancelled bookings notifications to multiple email addresses, go to your Appointedd calendar screen:
Hover over the Your business tab and click Business profile
Scroll down to the subheading Communication details
Under Other email addresses, add the addresses to which you would like to send all business notifications, separated by commas.
Business notifications will now be sent to any email addresses in this field, as well as the email address on your account (which you log in with).
You can also choose to send notifications to each of your resources when a new booking is made for them. Check out this guide to set this up.