I forgot my activation lock code and my previous iPhone is not working. How can I connect my watch to my new fone ?

the activation lock is not really on

the wqtch it's a theft protection measure on apples servers

it needs to be removed

About Activation

Lock on your Apple Watch - Apple Support

if you don't know your appleID

Recover Your Apple ID - Apple

if that does not help you then you need the assistance of apple

Additional Support - Activation Lock (apple.com) and or

Get Support (apple.com) , Genius Bar Reservation and Apple Support Options - Apple

See: If you don't have your old iPhone or you erased it How to pair your Apple Watch with a new iPhone - Apple Support

You can ask apple to remove the activation lock online on this page;

Online Activation Lock Removal Tool.

Or this;

If you can't remember/gain access to the apple id that paired the watch to the phone.Take the watch and it's receipt along with some photo id and any other proof of ownership to an Apple Store and request that they remove the Activation Lock for you.