This video covers the Android Installation from start to finish: setting up the app on your child's phone or tablet, linking the device to your account and then granting the permissions that Child Control needs in order to work at all.
Have your account details ready before you start, and pick up your child's device – the app is installed there, not on your own phone. Expect Android to ask about permissions more than once; that is by design, not a fault.
To read the steps instead, see the Android installation guide. If something gets stuck, the Android FAQ is the next place to look. Installing on a Google Pixel or a Xiaomi device differs in a few steps – those have their own videos. All of them are listed in the video overview.