how do i log in to icloud with my non-email apple id
I have had an apple id for several years. I bought a MacBook Pro and am trying to use iCloud. It tells me to log in with my apple ID, but then tells me it isn't valid. So I tried to create an @icloud.com account, but it won't let me. How do I use my valid apple ID (the one I used to log in to Support) for iCloud? Or how do I create an #icloud.com and transfer all of my purchases to it?
MacBook Pro with Retina display, OS X Mavericks (10.9.2)