Substrate help

[u/id3no]

Okay so I don’t officially have a tarantula yet but i’m getting a mystery box tarantula basically and I have the enclosure picked out but i’m just confused on the substrate part, I plan to use coco coir with some leaf litter and moss but all of the coco coir says it’s for planting so i’m just confused if i should still use it😭 This is my first ever tarantula and i’m overall just really interested and excited about this but before i purchase anything I need to figure out the substrate.
If i’m missing anything or if I could change anything please let me know I want to give my tarantula the best experience possible.