Well your need to add an "FTP" prefix if viewing via an internet browser, if you use an application there will be some text boxes to input your information.
If you dont have an FTP account set up as default, go into your Cpanel and create one. You are allowed to create 3 "FTP" accounts as far as im aware.
If you are using your web browser as your FTP client, then it is ftp:// instead of http://
You have a FTP account by default, it is the same as your cPanel info. Also, the amount of extra ftp accounts you can have depends on the package you have