Normally when you create a new Event in your calendar you'll see a shortened version of the event editor. This short event editor shows you only the basic that you need to create an event in your calendar. We do this to make it easier for you to quickly create events in your calendar. If you want to see other options for your events you have to click on the "More Options" button to see your full event editor. See the image below:

If you don't want to have to keep clicking the "More Options" button in the event editor to see the full event editor you can go to the "Customize" screen and choose to always see the full editor. Follow the steps in the image below: