Bio active enclosure

Hi! I’m going to start growing live plants in my ball python’s enclosure :) specifically looking at all kinds of photos. I have been trying to do some research on this, but I would really appreciate some guidance. Is miracle gro fine to put in my baby’s enclosure? Should I mix both her substrate and the soil? Only put the soil under her substrate? Only out soil where the roots are gonna be? So many questions I’m so sorry hahaha. I’m just really excited to start my bio active enclosure journey and want to do it right.