You need to create all the formats, required by your publications, based on the graphical project (in case of new publications), or on existing formatting (in case of switching from another system to GN4), or you have to import formats and styles from GN3 database (in case of upgrading to GN4 from GN3).
See Create or edit a format and other topics in the Editing GNML Formats, Libraries and Styles chapter.