In my experience, kids already get plenty of opportunities for screen-based STEM stuff. Mine have Hour of Code that offers block programming tutorials that are relatively fun. If they're anything like we were, they'll self-teach computer stuff when they're ready.
So I don't do much of that, and instead find other, more hands-on things I'm curious about and we can explore together.
There's a million different lessons you can teach about them, point is letting everyone have fun and possibly sparking interest in some of them.
Don't sit them in front of a computer screen or expect them to sit through a lecture.