how do i pair my iPhone with my new iPad?

iPhones and iPads are not “paired” together.

They are each setup and communicate directly to the internet via WiFi and/or Mobile Data.

There is rarely - if ever - any need to connect them together via a cable.

See:

Set up your iPhone or iPad - Apple Support

That's correct. iPad and iPhone do not pair with each other. You use the same Apple ID on both and you sync data between them using iCloud. There is no reason to need to pair them at all.