the email that my apple watch isn’t mine so i can’t connect it because i don’t know whose email it is to put in the password. what do i do?

Activation Lock is an anti-theft feature that cannot be bypassed. Only the previous owner can remove the lock with their password. If the previous owner cannot or will not remove the lock then the watch is useless to you or anyone else. Apple will not help you find the previous owner. Try to get a refund or dispose of the watch properly.

In the future see the 'Before you buy a watch from a third-party' section of:

What to do before you sell, give away, or trade in your Apple Watch, or buy one from someone else - Apple Support

If your mom is the ORIGINAL owner, see the 'Start a support request' section of:

How to remove Activation Lock - Apple Support

or perhaps:

If you forgot your Apple ID password - Apple Support

You're welcome.