The Start Center is a convenient place to get started with recent documents.
Opening it reveals a list of the most recently opened documents in the right pane – meaning there’s no need to worry about where they are saved. Closing an open document (as opposed to the whole window) will take the user back to the Start Center. Apart from the standard menu, clicking on one of the programs in the left pane opens that component of LibreOffice (Writer, Calc, Impress, etc.) as a new document. The buttons at the bottom, Help and Extensions, are for help documentation and for finding and adding extensions, which are basically add-on packages that offer additional functionality.