I don’t know! It is your username and password for the server that you are trying to connect to. If you do not have an account on a file server, you don’t need to use WinSCP! If you have an account on a file server at your place of work, or at the company which hosts your website (for example), you should contact their IT Support department to be reminded of your logon details.
It is also possible that you are trying to use WinSCP for a purpose for which it is not designed. WinSCP needs a SSH, FTP or WebDAV server to be installed at the other end (on the machine you want to connect to). In particular, you cannot easily use it to connect to another Windows workstation, since Windows does not have an SSH, FTP nor WebDAV server included by default.
Learn how to use WinSCP to exchange files.