iPad: time font on Home Screen
How to change font used for time display on iPad Home Screen?
iPad mini 6 Wi-Fi
Display customization is not a feature of iPadOS 16.2, though it is a feature of iOS 16.2.
On iOS, Settings > Wallpaper.
Not available on iPadOS 16.
If you’d like to see Apple add this to iPadOS, send them some feedback: Product Feedback - Apple