You can just go to your lock screen and let Face ID unlock it.
Hold the Lock Screen, and then it will appear the thing that lets you create a new one. Don’t. Click the one you have and customize and you should be able to select a new one from your photos
Definitely android does this better and i found it very annoying when I switched to iPhone this year
I can’t have the phone vibrate, but make no sound when I get a notification, without that affecting other system sounds?