Welcome to Dakka, seems like you're well on your way into the hobby already.
I'm a
40k player myself, so I can't speak to the specifics of
AoS, however, the best way I've found to both learn and/or teach any big tabletop game like these is to not worry about the minutia at the beginning, just get the basics down and slowly build off of that, adding layers of complexity as you go until you've got the hang of it.
Best of luck to you, my son's just getting into
40k so I know how much fun you must be having sharing a hobby.