Add a normal information page

Step 1: Creating a Page

First, go to the Pages > Add new, after filling the title input field, I suppose it will be About us, and save the page.

If this is just a regular information page, just enter regular text and click "Save change"

Step 2: Customizing template for About us page

If your page has some special information, you can create a template for it

Go to Templates and Create new Template like this:

Use the Text Block to add the description and others block information

Step 3: Assign template for Page

Go to Page list and open the "About us" page  that you have created, Template Settings in the right side