You should think first about the layout of the accordion. If you use tt_content elements, only the header and the bodytext will be displayed. If you use pages and tt_content elements, then the page title will be displayed first. After clicking at the page title, you will see the content elements of that page. If you use news, the categories are displayed first, thats why every news needs at least one category. After clicking at a category, all news-titles are shown. Than you can click at a news-title.
Put your content elements to a folder and select that folder in the plugin.
You can change the layout of the result. See chapter “Administration”.