If I do not have a Google G Suite Account or Outlook account, can I sync my calendar?
Yes, you can use Subscribe to my Calendar in the Calendar tab. This allows you to see your calendar in your own email program. Please keep in mind this is not bi-directional, nor is it a true sync; it's one way and read-only.
At the bottom of the Calendar tab, there's a link that says Subscribe to my Calendar. Clicking on it prompts you to download a .ics file which you can import into your calendar application.