Initial user sign up process issues in Pro Sites

Hi. New to pro sites and I'm unsure how new visitors sign up for their initial free blog.

From the landing page I can direct new visitors to either the login page or the pro sites page. On the login page they have to click register, which takes them to pro sites page. How do they simply get their free starter blog? I don't think I need to make a free level in pro sites??

I want to have a landing page button that new visitors can click to go to a sign up page for their initial free blog.

Thanks in advance.