You can also select the Directories menu, go to Change Directories, and enter the name of the directory you want to move to. Be sure you have the correct transfer mode selected. Use MacBinary II to store the file on the remote machine. Use BinHex if you want to mail it to someone. Use Text, Wrapped Text, or Raw Data if you want to manipulate the file on the remote machine.
More detailed help is available under the help menu.
To leave Fetch, go to the File menu and select Quit.