Training video for iWatch notifications

Wearing my iWatch blocks text message notifications. I have read this is by design. All the other notifications may also be getting blocked.

Is there a training video on this? Because the notifications section of the watch app is several pages long and does not explain how do not disturb or focus changes all of this.

I have tossed my watch in a bin as I have upset too many customers due to missed text messages. This issue outweighs all the watches benefits.