Init.cs

//gets called on the local instance from the OnGameLoad, will only be called once obviously
void Configure()
{
    Debug.Log("Manager Configured, Called Once The Game Loads, Right Before The Scene Load");

    SceneManager.sceneLoaded += OnSceneChanged;
}

//listener to scene change event, calls the Init method
private void OnSceneChanged(Scene scene, LoadSceneMode loadMode)
{
    Init();
}

//gets called on scene change, should act as a replacement for a monobehaviour's Awake, Start, .... methods
void Init()
{
    Debug.Log("Manager Initilized, Called On Every Scene Load Including The Startup Scene");
}