Why so many pages? What are they for and what do they mean?

Hello there to any and all who can provide a bit of assistance to this computer-challenged yet kind-hearted soul. After setting up my site to look like that of the gridsby demo, it seems now a multitude of pages have been created which I did not create. They are part of the home page menu as well. They are under names such as “shortcodes,” “buttons,” and “columns” for example. When you click on them, a brief explanation is given as to what they are, but why were pages created and added to the website for these items?

What is the purpose of these pages? How did they get there and should I simply delete them? Excuse my ignorance. The gridsby tutorial has no explanation that I’ve been able to catch.

Thank you in advance. Thanks for the great support thus far as well.

My site – https://www.wildwonderment.com