5. About Page
This page uses "Default Template" you can find inside the "Page Attributes".
5.1 Content Part
First comes the featured image you can include but you don't have to. Dimension of the featured image inside the live demo is 2440 x 987px. Under the featured image is the page title. Under the page title is the content from the editor. On the right is the sidebar.
To add widgets inside the sidebar navigate to the Appearance > Widgets and drag and drop widgets inisde the "Sidebar"
If you want to have the text widget to look as it does in the live preview please use the "Text Widget" and this code inside:
Text widget image size used in the live demo is 300x300px