The Recent Documents list on the left, shows the last 10 documents you opened. You can clear it by using the File Menu > Open Recent > Clear Menu. You may have to restart Xbase for the changes to take effect.
The bottom bar has three buttons. The Quit button quits Xbase, prompting to save any changed documents. The Open button displays a file browser and lets you open an existing document. The New button creates a new document.
The rest of the screen is taken up by Templates. The search bar (top-center), allows you to search the online repository of templates, submitted by users of Xbase. The center pane shows a list of search results and downloaded templates, if any. Double click a template to create a new document from it. The right pane shows a description of the currently selected template, with keywords at the bottom.