Are you that very same user? You’ll never be able to join the staff group, but that group is not associated with your home directory.
What I see you doing is doing a listing of /, which is root of the server - not your home or domain “root.” If you want to examine your directory, use ~/ or just ~. The tilde means “user’s home directory.”
FTP is different in that you are sandboxed into ~, so a / in FTP is really /home/rupert160 (or whatever) in SFTP and shell.