In the Listview you see at the start you have an overview of all the data you have entered. The days til column is how many days there are til the event occurs. 

To edit one of your events double click on it in the Listview, it will then in another window, ready for editing, or deleting. 

The Calendar found in the Settings tab is a viewing aid. It has no other function other than to help you keep track of time. 

You have several default settings you can choose at your pleasure. You can have PS Birthdays Organizer to show all upcoming events when the program starts.