To create or remove pages like About Us, Delivery Information and Terms & Conditions, you can do so at Catalog > Information.

Click Insert to create a new static page or select the page that you want to delete and click Delete.

You will see 2 fields available which are Information Title and Description.

For example, if you want to create an About Us page, put About Us as the title and all your content in the Description area.

You can also upload images and paste them inside the description field.

Sort it if you like and leave the rest of the options as default.

Click Save and the page will publish.