When you first open Fetch you are presented with the sign-on dialog box; at other times you can choose New Connection... from the File menu in order to see that dialog. The sign-on dialog has fields for entering three pieces of information:

The name of the machine you wish to transfer files with (or "host name"): The hostname = your server (ex: www.sunyrockland.edu)

The name of your account on that machine (or "user id"): Username = your account name

The password for that account: Password = your password