How to create a premium minecraft account for free?

Today at school, my friend gave me a USB with a full downloaded version of minecraft on it. When i got home i opened it up it came up with the full game launcher, i tried logging in with my minecraft.net email and password but i came up with can't connect with minecraft.net. I told my friend and hes like, "you need a premium account" and because i don't have any money i acnt buy one. Is there a way to get a free one? I've tried looking around for a site where i can get one, but they all have surveys you have to complete to get it… I just one a simple and easy site…
Please help…