The best way for kids to read and understand the KJV is to take them to a KJV-only church from birth. That’s how my siblings and learned. I was born on a Wednesday and in church four days later. Basic immersion is the best way.
And weren’t Sword Drills fun? I kicked butt. I don’t know of any churches who do that any more.
I remember sword drills.
My Father kept score and each month the high scorer would be given a Bible. Naturally a KJV.