Most hosting providers include instructions for managing FTP users in their support centers.
Below are links to a few hosting providers' instructions for finding FTP information:
Keep in mind that the FTP user you create must have access to the directory that you wish to backup.
Please take a look at this video tutorial for How To Add A Website. We will walk you through an example of how to locate your SFTP/FTP information.
If you aren't sure how to locate your SFTP/FTP information, you can always contact your hosting provider, and they'll be happy to assist you.