don't understand how to provide "membership" subscription in a page

Hi I followed the installation & use instructions but I didn’t understand how to allow my user to request registration to my site.

I need 2 types of registration: 1 is free and out of control/automatic (and the basic registration form of wordpress is ok), the other is free but it needs to be accepted by the admin (and i need an advanced registration form).

What can i do?

Thank you