There are two ways to create sides in Celtx. Let's take a look at how!
The Reports Page
The first way is to generate them from your Schedule Reports page. When you arrange your shooting schedule, and book it in the calendar, you can then generate sides for your shooting days in the shooting order.
The Sides Wizard
The Second way to generate sides, is directly from your script. Here's a quick video giving you a rundown on how to do that.