Page templates are pre-prepared pages consisting of demo content that serve as a starting point for you to use to create your own Pages. They serve as a means to demonstrate what can be achieved with Pages, along with preventing you from having to start from scratch. Each template has a name denoting it's suggested usage such as 'Homepage 1', but feel free to use the template for any purpose, the names are more to provide inspiration.
The Page Templates are presented upon start a new page, and will look something like the following:
If you hover over any of the templates, you'll see it's name - along with two buttons: 'preview' and 'use template'. Preview will open a new tab and show our demo store with that particular template in use - and use template will have the template loaded into the Pages Builder - from where it can be modified and saved as your own.
If you do not want to use a template, then simply select the first option, for 'Blank page'.