I need a Level Buying system, can you help me?

I am working on a game and I want the player to be able a passageway to the next area using coins. I have tried going through a tutorial and It didn't work and I would really appreciate a helping answer.

Here is my ontouched Script:

local cooldown = false

function onTouched(hit)
    if cooldown == false then
        if hit.Parent:FindFirstChild("Humanoid") then
            cooldown = true

            local BuyGui = script.Parent.Buy
            BuyGui:Clone().Parent = game.Players:FindFirstChild(hit.Parent.Name).PlayerGui

            wait(5)
            cooldown = false
        end
    end
end

script.Parent.Touched:Connect(onTouched)

Gui Script:

local BuyButton = script.Parent.BuyButton
local CancelButton = script.Parent.CancelButton
local Click = script.Parent.Click
local MainFrame = script.Parent
local ReplicatedStorage = game:GetService("ReplicatedStorage")
local BuyPassage = game.ReplicatedStorage:WaitForChild("BuyPassage")
local player = game.Players.LocalPlayer

BuyButton.MouseButton1Click:Connect(function()
    Click:Play()
    MainFrame.Visible = false
    BuyPassage:FireClient(player, "Spawn")
end)

CancelButton.MouseButton1Click:Connect(function()
    Click:Play()
    MainFrame.Visible = false
end)

ServerScriptService RemoteEvent Handler:

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local BuyPassage = Instance.new("RemoteEvent", ReplicatedStorage)
BuyPassage.Name = "BuyPassage"


function OnFiredEvent(Player, Passage)
    if Passage == "Spawn" then
        game.Players:FindFirstChild(Player):WaitForChild("leaderstats").Coins.Value = game.Players:FindFirstChild(Player):WaitForChild("leaderstats").Coins.Value - 100
        game.Workspace.Map.Spawn.Passage.Part.CanCollide = false
        game.Workspace.Map.Spawn.Passage.Part.Transparency = 1
        wait(1)
        game.Workspace.Map.Spawn.Passage.Part.CanCollide = true
        game.Workspace.Map.Spawn.Passage.Part.Transparency = 0.75
    end
end

BuyPassage.OnClientEvent:connect(OnFiredEvent())

If you know how to help me please tell me.