How to create a game navigation menu

So I have this project that required me to create a flash game. I made one, but I’m having a hard time adding a menu or a button where the user has to press play to start the game. So when the game opens, you should be required to press the “Play” button in order to play the game. I tried to google up my answer, but I can’t seem to find it. I posted my game file if you guys are wondering what it is. Any help?