Keep android phone off until I press combination of volume + power I'm using Asus Zenfone Max Pro M2 running on android pie.
My problem is there's kid at my home and he play with phone though it is protected with pattern he start all options from navigation bar or power off phone.

First I want to block notification bar completely I won't it scrollable.
Second I want kid prevent from turning phone switch off.

So how can I make my phone won't wake up or screen on until I do something special?
Your best and only bet is to root the phone. There may be an xposed package that will be able to give you the functionality you want. Look into the Magisk platform. I wasn't able to find a package for it but that does not mean it doesn't exist. 

As far as on startup or shut down, what you described is impossible. That's controlled by the phone bootloader and cannot be changed. Attempting to do so can destroy the phone permanently.

Note that any of these procedures will void your warranty.