Hello Super__Sa,
To start, do you want the Mac to get phone calls on it? If not then you'll want to turn off the Calls on Other Devices feature. On your iPhone go to Settings > Phone > Calls on Other Devices. On your Mac, open the FaceTime application then select FaceTime up in the menu bar > Preferences > Calls From iPhone.
Make and receive phone calls on Mac or iPad
If you want the Mac to get calls on it, but don't want it to notify you, you can turn off the notifications with these steps:
1. On your Mac, choose Apple menu > System Settings, then click Notifications in the sidebar. (You may need to scroll down.)
2. Click FaceTime on the right, then turn off “Allow notifications.”
Change or turn off all notifications from FaceTime on Mac
If you just want to silence the notifications temporarily, go into Control Center and turn on Do Not Disturb (this will silence all notifications on the computer).
Turn a Focus on or off on Mac
If you want to stop notifications on the watch, go into the Watch application on your iPhone > My Watch tab > Scroll down and select Phone, then change the notification setting from "Mirror my iPhone" to "Custom". After selecting Custom, select the "Notifications Off" option.
If you want to silence the notifications temporarily, you can either put the watch in Silent Mode (the watch will still vibrate for notifications) or Do Not Disturb (the watch will not give any sort of notification). To enable one of those, just bring up Control Center (swipe up from the bottom of the screen) and turn on the bell icon (Silent Mode) or the moon icon (Do Not Disturb).
Change the audio and notification settings on your Apple Watch
Cheers!