SceneManager.LoadScene

Hello, from the unity docs:
''Additive loads a Scene which appears in the Hierarchy window while another is active."
SceneManager.LoadScene(“YourScene”, LoadSceneMode.Additive);

my question, how can i get back to the main scene? i want only the main scene to be always loaded.
any way to see what scenes are currently loaded?

is better to have a one gigantic scene, or a main scene and 5 others very little ones, and use this “LoadSceneMode.Additive” to switch between the main and the little scenes?
the little scenes are basically UI.
its a mobile game.

thanks alot

I’d have it all in one scene, and just activate/deactivate the canvas (or elements within the canvas) as needed.