I made my son a YouTube Channel

My son (7) and I made a YouTube channel strictly for the fun of it.. he watched Minecraft videos and wants to have his own channel. We are not trying to make money, I understand the amount of work that would be and that’s not us.. but I have no idea where to even start. I have questions:

• What is an easy app or program to use to edit videos? He wants the typical screen record on the main screen and then a little rectangle in the corner with his face.. and commentary as he plays.

*What equipment do I need at the least? I have an iPhone, a computer, an Xbox, and a switch.. I assume I at least need a microphone.

*Whats the simplest routine? Screen record with a mic on a PC, I assume.. with a camera on his face as well and then clip it together?

Thank you!

ETA: this will be a private channel, my son just really wants to see himself on videos and learn how to do it. I appreciate the concern, I just simply want to know how to edit videos and put them on his private channel.