Apple Watch
I no longer have access to my Apple Watch because I no longer have access to the I cloud that’s linked to it when I try to pair it with a different phone what should I do ?
Restore an access to your previous Apple ID in order to remove an Activation Lock, so you could pair your watch with the new phone.
These links might be helpful
If you forgot your Apple ID - Apple Support
If you forgot your Apple ID password - Apple Support
Recover your Apple ID when you can’t reset your password - Apple Support