He's 11 and now beats me sometimes. I have complicated feelings about this.
My sister called and asked if I could get her son set up with 'the controller thing' before his birthday. Twenty minutes over FaceTime, we had it done. A few things I learned watching him use it.
Kids do not read tutorials. They just press things until it works. This is actually a great debugging strategy and I've adopted it for other apps.
He kept accidentally binding the wrong buttons because he wasn't looking at the screen while pressing the controller. If you're setting this up for a younger player, sit them in front of the screen and remind them to actually look before they map each button.
He picked up flip cancels in a week. It took me a month. I asked him how and he said 'I just did it.' I hate him.
Also: turn on the guest quick chat filter. Just do it. The comms in ranked are not for children.