You can create an event in Calendars for Mac in a few simple steps. Here's how:
Open Calendars by Readdle.
Click + at the top right.
Add a title to the event. With Calendars, you can create events by simply typing a descriptive title in plain English. The app will recognize the input and schedule an event for you. Want to meet John at Starbucks at 4 p.m.? Just type this, and Calendars creates an event.
Make sure all the needed settings of the dialog are finished, and click Save at the bottom.