So I'm using the script from the wiki page that just allows you to spawn in Los Santos and create a vehicle but when I start the resource for the server nothing happens, it just shows a black screen. 
function joinHandler() 
    local x = 1959.55 
    local y = -1714.46 
    local z = 10 
    spawnPlayer(source, x, y, z) 
    fadeCamera(source, true) 
    setCameraTarget(source, source) 
    outputChatBox("Script Testing", source) 
end 
addEventHandler("onPlayerJoin", getRootElement(), joinHandler) 
  
function createVehicleForPlayer(thePlayer, command, vehicleModel) 
    local x,y,z = getElementPosition(thePlayer) -- get the position of the player 
    x = x + 5 -- add 5 units to the x position 
    local createdVehicle = createVehicle(tonumber(vehicleModel),x,y,z) 
    -- check if the return value was ''false'' 
    if (createdVehicle == false) then 
        -- if so, output a message to the chatbox, but only to this player. 
        outputChatBox("Your vehicle wasn't created.",thePlayer) 
    end 
end 
addCommandHandler("createvehicle", createVehicleForPlayer) 
 
How can I fix it? I want to get good at scripting so that I can script for a race server.