multisite – cannot add subdomain

Hi my first post here!

I just activated the multisite by changing the wp-config file, creating a .htaccess file. (i called it phlogger.htaccess and placed in root and subdomain)

I can still logon my website (andrewwalmsley.info/phlogger) but when I choose anything from the mysites > network admin, all I get is are blank pages.

I followed tutoriall about adding wildcard but unsure if i have done this correct – the website runs from bluehost shared host.

Basically i want to add sub domain andrewwalmsley.info/portfolio sort of thing.

Please help