Racing game help?

Tracks = game.Lighting.Tracks:GetChildren()
player = game.Players.LocalPlayer
Wtracks = game.Workspace


h = Instance.new("Hint", game.Workspace)
ingame = false
TestrackSPAWN = false

while true do
    h.Text = "Choosing Track!"
        wait(3)
        ranTrack = math.random(1, #Tracks)
        trackChosen = Tracks[ranTrack]
        h.Text = "Track Chosen is " .. trackChosen.Name -- The track was chosen
        wait(3)
        trackChosenClone = trackChosen:Clone()
        trackChosenClone.Parent = game.Workspace --Track is now in game
        if trackChosen.Name == "Testrack" then
            local Testrack = game.Workspace.Testrack
            local finish = game.Workspace.Testrack.finish
            local Blocker = game.Workspace.Testrack.Blocker
            local poocrap = game.Workspace.Testrack.SpawnL
            ingame = true
            player.Character:MoveTo(poocrap.Position)
            --Countdown until race begins
            for i = 10, 1, -1 do
                h.Text = "Race begins in " .. i
                wait(1)
            end
            Blocker.Transparency = 1
            Blocker.CanCollide = false
            --Countdown until race runs out of time
            for i = 130, 1, -1 do
                h.Text = "Time left: " .. i
                wait(1)
                h.Text = "Race over, nobody finished.."
                trackChosenClone:Destroy()
            end
        end

    wait(1)
end

I'm making a racing game and I'm trying to figure out how to make a functional finish line. I've made a script that works like a minigame script to where it chooses a random track from a model named "Tracks" in my lighting folder that I made. I've been thinking on making the finish line brick have a onTouched event so when it's touched, it declares the winner via hint or message and destroys the copied workspace racetrack but the thing is, I don't know how to make a script that selects the finish line brick. I thought I should make a variable but I don't know how to make it select the finish line inside the racetrack that has just been copied into the Workspace.

tl:dr I need to help on how to find out to make a variable of a part inside a model that has just been copied into Workspace from Lighting.

It may sound complicated because I suck at explaining things but I really want to make this game. If you know how to do this, please answer.