Welcome back.
I'll answer your question about authentication here.
When you register, the site sends you a confirmation e-mail to the address you used when you signed up.
For some reason, in most cases, it ends up in the 'junk mail' folder. Have a look in there and if you find it, it asks you to to respond via a link and when you do, you are 'authenticated'.
Hope that helps.
Ls x