If you want a page to be full width and not have a sidebar - simply edit it and change the Template dropdown to Full width.
If you want a sidebar - change the Template dropdown to Default Template.
This will display sidebar widgets on the right. You can change what is displayed there by going to Appearance > Widgets > Sidebar Pages
Advanced Sidebar Pages
This is the Advanced Sidebar pages plugin and is used to build up internal section navigation automatically. In our demo site we decided that Customer Help should be the parent page, and all the sub pages are within this.
One of these is Common FAQs. So we just edit this Common FAQs page and set Customer Help to be the parent.
Why Choose Hypermart - Sidebar Feature
It's a list with the feature class in the CSS Classes field at the bottom.
Testimonial - Sidebar Feature
It's text with the class testimonial in the CSS Classes field.