Old Apple ID
How do I eliminate an Apple ID? I have a new one and want to eliminate the old one
iPhone XR, iOS 14
Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac --> https://support.apple.com/HT208242
Click on this link to learn how to 'Sign in with your Apple ID' --> https://support.apple.com/HT204053
Make sure Find My is disabled for the old ID:
Turn off Find My on your iPhone, iPad or iPod touch