Veronica,
FCP places files in various locations on your drive. Some are preference files, some are links to projects, etc. I would start in the Library/Application Support/Final Cut folders. FC places plugins, etc. in these folders. There is also similar files installed in your home folder, again under Library/Application Support.
Since I am using FCP 6, I am not sure of exactly where and what the various folders are, but a search of your harddrive with Spotlight may reveal others. Of course Spotlight will only reveal files and folders that you have access to either as owner or as Administrator. It will also not show you any hidden files (those files that begin with “.”)
Hope this will get you started.
-DON-