Can anyone help me with a custom inventory system?

I am creating an inventory system it can contain custom tools not roblox tools.

Here is my script currently:

Inventories = {}
InventoryTemplate = {game.ReplicatedStorage.ItemTypes.Sword}

-- setting a player's inventory below
game.Players.PlayerAdded:connect(function(player)
	Inventories[player.Name] = InventoryTemplate
end)

I have no idea what to do now...

Thanks.

I bet some of the experienced coders will say it's not that hard, but making a good inventory can be complicated sometimes, besides you shouldn't save the instances directly.