Hello again,
Here are some more answers for you.
1. Are we can set private and public for each events.
Absolutely. It works exactly like any normal WordPress post or page.
2. Every user can create events?
As long as their user role has the proper capabilities, yes.
You might want to read the following to have a better sense of how you can control that: https://theeventscalendar.com/knowledgebase/admin-roles-and-permissions/
3. If yes, They create event and make it as private means no other could not see this events (bith login and non-login users). Until they make this event as public.
If you want non-logged in users to create events, you will need to grab a copy of our Community Events premium add-on: https://theeventscalendar.com/product/wordpress-community-events/
This would provide you complete control over the process.
Let me know if that helps.
Have a great day!
Geoff B.