All scenes are already loaded when I start the game. How do i only load one?

Hi I'm trying to make a starting page where i can click play button to move to gameplay scene. I made the button and loading scene part, but the problem is that once i start the game, the gameplay scene is already loaded and gameplay scene's main camera is showing gameplay map in the background. sure i could cover it up by giving a background image to the starting menu but that wouldn't be efficient as the device is running 2 scences for nothing.

Summary: How do i ONLY load the starting scene?

Thanks!