How to connect iPad Pro to iMac
What cable(s) do I need to be able to connect and sync my new 3rd generation 11-inch iPad Pro with a 2017 iMac?
Just the USB-C charging cable that comes in the box with the iPad. Nothing more.
Your iMac has 2 USB-C (Thunderbolt 3) ports that can be used with the iPad and its charging cable.