My inventory script doesn't work, the inventory isnt in the gui, help?

I've been working on a inventory gui lately but i got into some problems here is the gui: ! I want to create a custom inventory where you can select the item u want and equip it, if it's a helmet,armor,weapon or something it will be placed on a certain place such as the head of the character. So if item = helmet then item equipped on characters head.

If you can help please comment down below, i'd really appreciate the help because i've looked for a solution for many hours :)

this is my script so far: game.player.LocalPlayer.backpack = startergui.inventorygui.weaponslot if item.equipped = helmet then equipped.helmet.character.head