The events your guests can see and access are determined by your privacy settings. To review how to enable or disable event privacy, please see here.
If you have made your events private, then here are a few scenarios:
Non-invited Guests: These guests will see something like the below in a multi- or single page site. If they attempt to log in to view the private events, you will be notified. You can then accept or decline the request. If you decline, they will not be notified.
Invited Guests (Logged In): These guests will see all public and private events in your events section.
Invited Guests (Not Logged In): These guests will have the same view as non-invited guests, but when they log in successfully (either their name or email matches your Guest List), then they will see all the private events they have been invited to as well.
If all of your events are public but you have enabled Guest List Match on your site, then all guests will be able to see your events, but they must enter name and email to be able to RSVP.