I think the #1 thing for kids (at least ours) is to make sure they are having fun . When they're that young, if they are not having fun they will quit.It happened to me when I Was a kid...
I use a machine for practice. It's not the real deal but it helps me with my swing. I bought it online somewhere, it is a heater sports I think i got it from here: https://pitchprodirect.com/collections/spinball-pitching-machines
If dropping a link isn't allowed, just let me know and I will...