Level Load Display Delay

I'm working on a minor element of my current project that involves a visual effect and sounds playing at the start of a level, before anything happens. In order to do this, I have several things set to happen on Awake when the level is loaded.

Unfortunately, there are a few issues. If I start up the scene directly in the editor, it starts half a second in. If I go through from the game's main menu, I hear that half-second from the loading screen before it starts to show the visuals and plays the rest.

Is there any way to make everything wait until the screen is actually displaying the scene? Normally I'd just do this the crude way and have it literally wait half a second, but I presume the gap of time before it starts displaying stuff would differ based on hardware setups.