I can't connect my Apple Watch with my iPhone

Your watch and iPhone need to use the same Apple ID. Unpair and erase the watch from the old Apple ID first. Here are two ways to unpair your watch if you no longer have the paired iPhone:

• See the 'How to erase your Apple Watch if you don't have your iPhone' section of:

Unpair and erase your Apple Watch - Apple Support

• With a web browser, go to: https://www.iCloud.com and sign in with your Apple ID. Open Find My iPhone and select All Devices (at the top). Then click your Apple Watch, select 'Erase Apple Watch', and select Next until the device is erased. Finally click "X" next to remove your Apple Watch.

Both devices have to use the same Apple ID. There is no way around this.