Line 10 reads "attempt to index nil with 'Clone' why is this?

local LevelReq = script.Parent:WaitForChild("LevelReq").Value
local Price = script.Parent:WaitForChild("Price").Value

script.Parent.MouseButton1Click:Connect(function()
	local Player = game.Players.LocalPlayer
	local Stats = Player:WaitForChild("leaderstats")
	local Level = Stats:WaitForChild("Level")
	local Gold = Stats:WaitForChild("Gold")
	local Tool = script.Parent.Item.Value
	local CTool = game.ReplicatedStorage.ToolLibrary:FindFirstChild(Tool):Clone()
	if Player.Backpack:FindFirstChild(Tool) or Player.Character:FindFirstChild(Tool) then return end
	if Level.Value >= LevelReq then
		if Gold.Value >= Price then
			Gold.Value = Gold.Value - Price
			CTool.Parent = Player.Backpack
		end
	end
end)

script.Parent.MouseEnter:Connect(function()
	local Cost = script.Parent.Parent.Parent:WaitForChild("Cost")
	Cost.Text = "Cost: 3"..Price
end)

script.Parent.MouseLeave:Connect(function()
	local Cost = script.Parent.Parent.Parent:WaitForChild("Cost")
	Cost.Text = "Cost:"
end)

I've been pulling my hair out trying to fix the error on Line 10, the shop I've made opens and closes, just buying a tool is the part that doesn't work.

Try doing

local CTool = game.ReplicatedStorage.ToolLibrary:FindFirstChild(Tool)

Then add a line after this and put

local Cloned = CTool:Clone()