GUi for each item in folder is this possible?

There should be quite the number of errors, you must be using the incorrect Script type, or have it under a container that doesn't execute programs.

Let's list off the things you need to fix:

You're traversing through an array, therefore index-pairs is best suited for iteration.

The variable i refers to the current index, you'll get an integer instead of a string.

You created a clone and gave it no Parent.

You're not referencing the .Name property, you'll get two errors.

--###----------[[VARIABLES]]----------###--
local ReplicatedStorage = game:GetService("ReplicatedStorage")

local Weapons = ReplicatedStorage:WaitForChild("Weapons")


local GUITemplate = script.Parent



--###----------[[LOGIC]]----------###--
for _, Weapon in ipairs(Weapons:GetChildren()) do
    local GUI = GUITemplate:Clone()
    ---------------
    GUI.Name = Weapon.Name
    GUI.Text = Weapon.Name
    GUI.Visible = true
    ---------------
    GUI.Parent = --// Location.
end

local repStor = game:GetService("ReplicatedStorage")

local Wepons = repStor:FindFirstChild("Weapons")

for i,v in pairs(Wepons:GetChildren()) do
    local Gui = script.Parent:Clone()
    Gui.Name = v.Name
    Gui.Text = v.Name
    Gui.Visible = true
end

you make it i instead of v and you must put the Name or else the script won't understand what you wanted. If it keeps on looping then try this one

local repStor = game:GetService("ReplicatedStorage")
local Wepons = repStor:FindFirstChild("Weapons"):GetChildren()

for i=1, #Wepons do
    local Gui = script.Parent:Clone()
    Gui.Parent = game.Players.LocalPlayer:WaitForChild("Backpack")
    Gui.Visible = false
    Gui.Name = i[Wepons].Nane
    Gui.Text = i[Wepons].Name
    Gui.Visible = true
end

if it doesn't work please dm me on discord Blue Duck#9891 and try to be as specific as you can. Stay safe.