I was going to try to explain it, but realized I’m not very good at calling menus and such their proper names. So whatever I tell you wouldn’t be very helpful.
Apple also has a YouTube video that’s about 5 minutes long. The article is probably faster.
I’m not a power user, so I don’t use the majority of features on my phone. I generally set my “do not disturb” at bedtime. It allows calls through from my favorite contact list and my morning alarm. I have friends that set focus time and they love it.
Edit to add to the conversation. I disable all notifications, except for things I really want: calls, FaceTime, texts and to update my food diary if I haven’t done so before 2pm.
When I need to use Uber, I just keep watch on the app. I guess I’m a bit of a psychopath. But when I’m waiting for a car, I like to watch it move on the map. There’s nothing else I would use that would need me to have a notification.