Dads Apple Watch

It can’t be paired with you iPhone because the Apple Watch is already associated with his Apple ID.

The only way you may be able to use this Apple Watch is to take it to an Apple Store along with a certified copy of your dad’s death certificate.

To pair the Apple Watch to your phone you need to unpair it from your Dad’s phone (on the Watch app) first, then you will be able to pair it (be aware that you have to erase the data and reset to be able to use it with your phone).