Apple Watch and IPad

You can't pair an apple watch with an iPad, it has to be with an iPhone

Set up your Apple Watch - Apple Support

This might be relevant if the goal is to set up an apple watch for someone not owning an iPhone:

Set up a family member’s Apple Watch - Apple Support

Set up an Apple Watch for a family member - Apple Support

It does require Cellular-capable Apple Watch SE or Apple Watch Series 4 or later

You cannot,an apple watch will only pair and setup with an iphone.