The FAQ addon is quite simple to use. By default, there is no configuration at all. The questions are displayed using your theme’s default archive page, and single questions are displayed using your theme’s default single page.
However, if you want to customize the look of your FAQ, you can use the dedicated shortcode
The shortcode has a number of parameters available:
[faq cat="101" limit="5"]
Please notice that in order to restrict the shortcode to displaying just a single category, you have to use the WordPress category id, not the slug! To locate the WordPress category id you can go to FAQs->CATEGORIES and hover over any of the categories. The ID will be shown in the URL at the bottom of the browser. Or, if you click on the category, it will be shown as part of the URL in your browser bar. Look for the part of the url that says tag_id=nnn where nnn will be the category id.