Simple start mechanism

Hey, so i am trying to do instant gameplay when i clicked start button(my panel is start button) every game mechanism should start(same scene as start menu).
But i am concerned about my method if its okay for performance or sensible etc because its gonna check everytime for panel.

And this is my script for stopping all game mechanism;

void Update()
{
    if (Panel.gameObject.activeSelf==false)
    {
        //starting game
    }

One Update loop won’t kill your performance.
But if you really want to make it more performant, use OnDisable() / OnEnable() methodes in a script placed on the Panel gameObject.