I believe the right mental model is the first step towards understanding coding or computers. The easiest way to start for a kid might be with something that interests them - like creating shapes/graphics. (I am grateful for my school introducing me to programming via logo when I was nine)

I've been at it 2 weeks now trying to teach my grandma how a computer works. She now understands how a processor works, what is a software program, etc.

I made my grandma dictate code to make me dance giving her exactly 4 commands (moves) I could take (I am a 2-bit processor ;) ). We had fun! Ha. So she coded. No computers. I could also explain processor speed, n-bit processors, different instruction sets, instructions that need operands, etc. Of course I used none of these words.