how to create a inventory/bag like mmorpgs ?

i created this but it doesnt really help

local gui = script.Parent
local frame = gui.Frame
local button = gui.a1
local list = {"test"}
y = 0.3
x = 0.02
maxX = 0.87
maxY = 0.9

for i = 1,#list do
function new()
add = button:Clone()
add .Position = UDim2.new(y, 0, x, 0)
add .TextLabel.Name = list[i]
add .Parent = frame
x = x + 0.02
if x > 3 then
y = y +0.15
x = 0.02
end
end
end

button.MouseButton1Up:connect(function()
new()
end)