Hostname

Guys I know this is the Pc forum but idk where else to go. I just got a small job and the client gave me control of the website. All they gave me is the HOSTNAME, PASSWORD and USERNAME. All just numbers and letter. Can someone tell me how I enter the editing aspect of the site with this...

Hello, does anyone know what this statement means: Does IP Address comply with reverse hostname naming convention... Failed! I got this feedback from a blacklist we are on, but I do not know what it is and therefore. . can't correct it. Thanks.