connect new iPad to MacBook Pro to mirror onto my thunderbolt

it's unclear what device you wish to end up showing the image of the other

if you wish to get the ipads display to the mac you can use quicktime https://www.softwarert.com/mirror-iphone-ipad-to-mac-quicktime/

if you wish to use the ipad as second display for the MacBook you can use wired https://www.duetdisplay.com/?gclid=Cj0KCQjw1pblBRDSARIsACfUG12SuPGbWzX9jA1HWdBEx0MiD6LRAKAksGTEvb_Xoin8EdLTzW_u_bIaAnVKEALw_wcB

or wireless https://avatron.com/applications/air-display/

the display of ipads connecting to monitors by usb-c is only a thing for monitors because the display port of a MacBook is output only not a input

Greetings blaseamy5,

Thanks for visiting the Apple Support Communities! It seems you're curious how to connect your iPad to the Thunderbolt 3 port on your MacBook Pro.

The USB-C to USB Adapter will allow you to connect your iPad to your MacBook Pro: USB-C to USB Adapter - Apple

An adapter wouldn't be needed to mirror the display of your iPad to your MacBook Pro, as you can use AirPlay: How to AirPlay video and mirror your device's screen to Apple TV

Let me know how it goes from here.

Cheers.