Does Anybody Know How to Have An Inventory Set Up?

I really want to set up an inventory for C-17 Legendary Edition. I am going to add a village where NPC’s can sell weapons and armor, potions and even food… But i can’t do that until i set up an inventory.

Also: Another example could be where when you break the log of a tree, it goes in your inventory, and when you place it, it disappears from your inventory. If anyone could help that would be great thanks!

                                                                                                                                   -TommyX2X14

@jngthree @grazer

P.S The Game is Here
https://flowlab.io/game/view/271944