FaceTime and App Store are built-in applications in iPad, they cannot be deleted by default. If you find that FaceTime is missing from your iPad mini, check if your iPad is purchased or used in Saudi Arabia, Pakistan, and the United Arab Emirates, including Dubai. These places don't support FaceTime.
If that's not the case, check if you've turned on Screen Time for your Camera. If you've done that, you can't use FaceTime. You can reset your settings.
You can use Siri or Spotlight to search for FaceTime on your iPad. Also, you can also search for App Store.
For the deleted App Store, reset the Home Screen to show it:
Go to Settings, tap General > Reset, and then choose Reset Home Screen Layout to return the icons to default settings, then the App Store icon can be restored.
If still changes nothing, update your iPad.