You can create some registration types that you don't want to been seen publically but you still want to have them registered. Examples may be like Volunteer or staff positions for an event-- like speaker, worship team, kitchen team. You still want them connected to the event and count in the numbers, but those people will be registered by someone with admin permissions.
Advanced options are under the first page of setup Overview with the description and includes "customize email confirmation," "campus, "max capacity," etc. I'm not sure why you would not be able to see that section.