I need help removing my Apple Watch from my old phone but I don’t have my old phone anymore so what can I do .

See this, Unpair and erase your Apple Watch - Apple Support the section about if you don't have your phone.

To unpair and erase watch and remove Activation Lock

From a web browser,sign in to iCloud.com with your Apple ID.

Go to Find iPhone.

Click All Devices at the top of the screen.

Click your Apple Watch.

Click Erase [device]. Select Next until the device is erased.

Click Remove from Account.