Can I mirror my iPhone XR screen on my iPad 5th generation

Sorry, no. Screen Mirroring between iOS/iPadOS devices is not supported. For the most part, such a feature would be pointless - as the majority of Apps can be utilised by both iPad and iPhone.

For core native Apple Apps, Apple Continuity allows direct handoff between devices that are signed-in to iCloud with the same AppleID:

Use Continuity to connect your Mac, iPhone, iPad, iPod touch and Apple Watch – Apple Support