Game starts even on Menu screen!

Hey Unity Community,

So I'm a new game developer. Never had any knowledge on scripting and game development. I'm trying to create an endless runner game. I made the game scene, created a new scene for my main menu. The thing is that when ever I test out the game, it brings me to the main menu first (which is good) but in the background you can hear that the main game scene is already running (with sounds of crashing). Can anyone shed some light on what's happening?