Comment by roscas

First, it is really nice to see how many people use and know Linux and care about their kids being safe and care to teach them how to learn computer and programming.

Second, for such young age, you still need to manage the pc. So Manjaro with Plasma is my choice.

The software to install is your choice, because it really depends on what they will do, but Minecraft and other Minecraf-clones is a must and LibreOffice for their works.

Install LibreWolf with uBlock Origin, for their default browser. Keep Pi-Hole as the default DNS server and if you or them don't have one, buy a Raspberry PI and install one. That is a critical step. Best 70 bucks you will ever spend.