It’s better to start with a new subdirectory in Mike’s Projects, and point Cubase to this new directory when starting a new project (best done from a template). That way, all relevant files are already where you want them and mistakes can be prevented. Also file names make more sense that way - i.s.o. a new guitar track being called ‘Guitar_05’ because in other projects there were 4 completely different guitar takes. By using ‘remove unused files’ and deleting them via Trash, you make sure that you remain with anything that’s used in the project, and when done you can move the whole directory to a backup drive.