>>I’d like my form has an specific URL name
Sorry we do not allow URL renaming. You will have to use the URL provided in "Distribute" tab/Copy Link box.
>>So i have to use the embed code.Does anyone has a very simple HTML code that I can do that?
FormsCentral provides you the embed code that you can just copy/paste to your web page, please take a look at this link for more information: http://forums.adobe.com/docs/DOC-1991