"Create a login screen that has a picture background with play and quit buttons that work"

-- local script in StarterGui 
local screenGui = Instance.new("ScreenGui")
local frame = Instance.new("Frame")
local playButton = Instance.new("TextButton")
local quitButton = Instance.new("TextButton")
local imageLabel = Instance.new("ImageLabel")

screenGui.Parent = game.Players.LocalPlayer:WaitForChild("PlayerGui")
frame.Parent = screenGui
playButton.Parent = frame
quitButton.Parent = frame
imageLabel.Parent = frame

frame.Size = UDim2.new(1, 0, 1, 0)

imageLabel.Size = UDim2.new(1, 0, 1, 0)
imageLabel.Image = "rbxassetid://your_image_id" -- replace with your image id

playButton.Size = UDim2.new(0, 100, 0, 50)
playButton.Position = UDim2.new(0.5, -50, 0.5, -25)
playButton.Text = "Play"
playButton.MouseButton1Click:Connect(function()
    frame.Visible = false
end)

quitButton.Size = UDim2.new(0, 100, 0, 50)
quitButton.Position = UDim2.new(0.5, -50, 0.6, -25)
quitButton.Text = "Quit"
quitButton.MouseButton1Click:Connect(function()
    game.Players.LocalPlayer:Kick("You have quit the game.")
end)