The best way for you to see how the different formats look is to open the sample script included with the program.
Go to Help > Sample Scripts > Script.
Once the sample script is open go to Format > Elements (Mac) or Format > Elements Settings (Windows).
In the Elements window, choose Apply a Template.
Simply choose one of the templates (for example Single Cam Teleplay), then hit OK. The script is now rendered as a half-hour comedy.
If you don't want to use any of the ones provided you can use the Elements window to change or modify one to your specifications. See How can I change the way my script looks?