I need help getting into my old Apple ID account

Click on this link to learn how to 'Sign in with your Apple ID' --> https://support.apple.com/HT204053

'If you can't connect or sign in to iCloud', read the document at this link --> https://support.apple.com/HT203512

I have a problem trying to pair my apple watch to my new phone because the account has my old phone number and that is not activated anymore. Can u please help me