Use the credentials of your hosting as SSH login. The SSH login works neither with the Hostpoint ID nor with additional FTP accounts.
The username can be found in the contract of the webserver and the password ist set by you in the Control Panel. Open your server under "Services" and switch to the left to "Advanced". In the menu "Password Change" you set the new password for the hosting login.
On Linux and Apple OS X, you can use the terminal for the connection. On Windows, you need additional software, such as PuTTY or WinSCP.
The command for the connection is as follows: ssh firstname.lastname@example.org or ssh username @your-servername