Need IPhone to ring when someone calls

If your phone is locked, the watch will ring or vibrate (depending on settings) when you receive a notification. You can disable wrist detection in the Watch app on your phone which will cause notifications to sound on the phone. However, you will need to unlock the watch with a passcode whenever you want to do more than check the time and you will not be able to use Apple Pay from the watch.

I'd suggest taking the watch off of silent.

Use Control Center on your Apple Watch - Apple Support