If you do not already have a google calendar or another third party calendar source, you can easily set up the calendar within the dashboard of your site.
1) In the backend dashboard, hover over RJ Web Builder Calendar and click on Add New.
2) Within the Event editor page, you can give the event a title and add a description in the main editor (just like a regular Page or Post).
3) Then add 1) event dates, 2) event location, 3) event recurrence, the event category, title or content and a featured image if you wish.
4) If adding a recurring event, you can choose the frequency, the day of the week it occurs on and how long the series of events should last. You can also add any dates that should be excluded from the event series.
4) Once you've added all information, hit Submit then the blue Publish button.