On the Class Design Screen (F6), use "New Hull" to create the New "Germinal" class, it will ask you next for an abbreviation, the prefix used for short hand Identification (Like "DD" for Destroyer class, "CR" for Cruiser class etc). You will then be able to select Germinal in the Hull drop down box.
Next the names, while you can manually do this during construction, you can add a new list that will appear in the Name Type dropdown box of the DAC/Rank/Information tab on the Class Design screen.
Add a new list by creating a txt file called ShipNames.txt with the list of your ships names, remove all the accents and whatnots - ie "Floreal" will work, "Floréal" will throw errors on import. One name per line. Save that file in the Aurora install directory, and then from the main control bar, from the "Game" menu, choose "Add Ship Names". You will get a warning asking you if you have made the file, and how to go about making the file, if you have done it click yes and Enter a Category (for instance: "Germinal") Now Germinal will be an option in the Name type box and the game will use each name in the order typed.