Just Setup both with the same icloud account etc and all is the same... and in the settings settings iTunes and AppStore all on and even the apps are installed the same...
iCloud is accessible from all devices, just save nothing on device, all to iCloud Drive...
Calendar, notes, Mail etc all default as *****@icloud.com
Has the advantage as well that you can use emails with large attachments and you are asked if you want to use “Mail drop” if the size is more than 50MB
If you got MS office the same... ms account and all data to onedrive...
I do the same with 3 different iPad models (mini air pro) and a MBA... and a phone...