Collision detection with placement system?

So I made a very simple placement system that literally just places objects along a 2x2 grid. No rotation or collision. My problem is I want to detect collision between objects and then set a variable so you can't place the object. My localScript is in a GUI in StarterGui. I tried to detect collision with the Touched and TouchEnded events but that did not work. I tried those events in a Script and in the localScript I am using for placement. Here is my current code: Note > I am just placing a single part that is not even in a model.

-- Player Variables
local Player = game.Players.LocalPlayer
local Mouse = Player:GetMouse()

-- Position Variables
local PosX
local PosY = 2.1
local PosZ

-- Object Variables
local Gui = script.Parent
local Button = Gui.TextButton
local Baseplate = workspace.Baseplate
local Texture = Baseplate.Texture
local Model -- This is going to be a part

-- Textures
local GridId = "rbxassetid://13786085"

-- Snap to grid Variables
local Grid =  2
local Snap = 2
local Rounding = 0.5

-- Debounce
local IsPlacing = nil

-- functions

-- Snaps the part to a grid
local function Round()
	PosX = math.floor(Mouse.Hit.X / Snap + Rounding) * Grid
	PosZ = math.floor(Mouse.Hit.Z / Snap + Rounding) * Grid
end

-- Moves the part
local function Movement()
	if IsPlacing == true and Model:IsA("Part") then
		Round()
		Model.Position = Vector3.new(PosX, PosY, PosZ)
	end
end

-- Places the object
local function Placement()	
	if IsPlacing == true and Model:IsA("Part") then
		local FinishedModel = Model:Clone()
		FinishedModel.Parent = workspace.Clones
		FinishedModel.CanCollide = true
		
		Model:Destroy()
		IsPlacing = false
		Texture.Texture = ""
	end
end

-- Starts the placement
local function StartPlacement()
	Model = game.ReplicatedStorage.Movement:Clone()
	Model.Parent = workspace
	Model.CanCollide = false
	Texture.Texture = GridId
	IsPlacing = true
	
	Mouse.Move:Connect(Movement)
end

Button.MouseButton1Click:Connect(StartPlacement)
Mouse.Button1Down:Connect(Placement)

Thanks for the help!