Don’t have my old phone and my watch won’t pair with my new Apple

You will need to remove it from your old Apple ID. Why did you create a new Apple ID? You can continue to use the same ID with new devices.

Remove  Watch from Apple ID -

1. Go to icloud.com and login
2. Open Find iPhone.
3. In the All Devices pulldown menu select your Watch.
4. In the resulting sheet that appears to the right choose erase Apple Watch.
5. Then Remove the watch from your Apple ID.

M1 Mac mini, macOS 11.2; Watch, series 5 GPS/cellular, watchOS 7.3; iPad Pro 2nd Gen, iPadOS 14.4; iPad Air 2, iPadOS 14.4; iPhone 12 Pro, iOS 14.4; TV 4th Gen, tvOS 14.;  HomePods, audioOS 14.4 and Airport Express w/ Airplay 2