Roblox U game loop, help?

local checkpoint1 = game.Workspace.Checkpoint1
local checkpoint2 = game.Workspace.Checkpoint2
local checkpoint3 = game.Workspace.Checkpoint3
local show = false
local oldcars = game.ServerStorage:GetChildren()

local raceInProgress = false

function showVictoryMessage(playerName)
    if show == false then
        show = true
        local message = Instance.new("Message")
        message.Text = playerName .. " wins!"
        message.Parent = game.Workspace
        wait(2)
        message:Destroy()
        show = false
    end
end 


function destroyCars()
    if raceInProgress == true then  
        for _, object in pairs (game.Workspace:GetChildren()) do
            print(object.Name)
            if object.Name == "Car" then
                print("This is a car, we need to destroy it!")
                object:Destroy()
            end
        end 
    end
end

function createCars()
    for _, object in pairs(game.ServerStorage:GetChildren()) do     
        local oldcar = object:Clone()
        oldcar.Parent = game.Workspace
        oldcar:MakeJoints()

    end
end

function CreateCarsV2()
    for _, object in pairs (game.ServerStorage:GetChildren()) do
        local carClone = object:Clone()
        if carClone and carClone.Parent == game.ServerStorage then
            carClone.Parent = game.Workspace
            carClone:MakeJoints()
        end
    end
end

function checkpoint1hit(otherPart)
    print("Checkpoint1 was hit!")
    print(otherPart.Name)
    if otherPart ~= nil and otherPart.Parent ~= nil and otherPart.Parent:FindFirstChild("Humanoid") then
        print("A player hit me!")
        if not checkpoint1:FindFirstChild(otherPart.Parent.Name) then
            local playerTag = Instance.new("StringValue")
            playerTag.Parent = checkpoint1
            playerTag.Name = otherPart.Parent.Name
            playerTag.Value = otherPart.Parent.Name
        end

        if checkpoint3:FindFirstChild(otherPart.Parent.Name) and raceInProgress == true then
            print("Player wins")

            showVictoryMessage(otherPart.Parent.Name)
            raceInProgress = false
        end     

    end
end

function checkpoint2hit(otherPart)
    print("Checkpoint2 was hit!")
    print(otherPart.Name)
    if otherPart ~= nil and otherPart.Parent ~= nil and otherPart.Parent:FindFirstChild("Humanoid") then
        print("A player hit me!")
        if not checkpoint2:FindFirstChild(otherPart.Parent.Name) and checkpoint1:FindFirstChild(otherPart.Parent.Name) then
            local playerTag = Instance.new("StringValue")
            playerTag.Parent = checkpoint2
            playerTag.Name = otherPart.Parent.Name
            playerTag.Value = otherPart.Parent.Name
        end
    end
end

function checkpoint3hit(otherPart)
    print("Checkpoint1 was hit!")
    print(otherPart.Name)
    if otherPart ~= nil and otherPart.Parent ~= nil and otherPart.Parent:FindFirstChild("Humanoid") then
        print("A player hit me!")
        if not checkpoint3:FindFirstChild(otherPart.Parent.Name) and checkpoint2:FindFirstChild(otherPart.Parent.Name) then
            local playerTag = Instance.new("StringValue")
            playerTag.Parent = checkpoint3
            playerTag.Name = otherPart.Parent.Name
            playerTag.Value = otherPart.Parent.Name
        end
    end
end

checkpoint1.Touched:connect(checkpoint1hit)
checkpoint2.Touched:connect(checkpoint2hit)
checkpoint3.Touched:connect(checkpoint3hit)


local redLight = game.Workspace.StartLight.RedModel.LightBulb.PointLight
local yellowLight = game.Workspace.StartLight.YellowModel.LightBulb.PointLight
local greenLight = game.Workspace.StartLight.GreenModel.LightBulb.PointLight
local startBarrier = game.Workspace.StartBarrier

function startLightCycle()
    wait(5)

    redLight.Enabled = true

    wait(1)

    redLight.Enabled = false
    yellowLight.Enabled = true

    wait(1)

    yellowLight.Enabled = false
    greenLight.Enabled = true
end

function removeBarrier()
    startBarrier.Transparency = 1
    startBarrier.CanCollide = false
end

function resetLights()
    redLight.Enabled = false
    yellowLight.Enabled = false
    greenLight.Enabled = false
end

function resetBarrier()
    startBarrier.Transparency = 0.5
    startBarrier.CanCollide = true
end

function clearCheckpoint(checkpoint)
    for _, object in pairs(checkpoint:GetChildren()) do
        if object.Name ~= "TouchInterest" then
            object:Destroy()
        end 
    end
end

wait(10)

while true do
    --setup racetrack
    --turn off all lights
    resetLights()
    --reset barrier
    resetBarrier()

    --destroy cars
    destroyCars()

    --create cars   
    createCars()

    --clear all checkpoints
    clearCheckpoint(checkpoint1)
    clearCheckpoint(checkpoint2)
    clearCheckpoint(checkpoint3)

    --start race
    --start the light cycle
    startLightCycle()
    --remove barrier
    removeBarrier()

    raceInProgress = false
    --wait for race to finish
    while raceInProgress == true do
        wait()
    end 

    wait(10)
end

I watched the video and I copied the code character to character but it before the race is over, it will start the game loop from the beginning. It would make new cars and delete cars while the race is still in progress.