Am trying to work out membership wit pro sites

Hi folks.

I am trying to use membership to protect certain Urls from Visitors.

However now I see that I have to manually ad all my users to a level and now if any user logs in, they are blocked from everything i have blocked for visitors.

1.When new user signs up for new site with the "register" page, will the automatically get transferred to a level?
2. is it better to have people sign up with the "sign up" page from pro sites, however how will they then access content, totally confused.

I really do not want to have to manually ad new users to levels so they can access content, I just want the site to react as it has up tip now.

can anyone help me with this please?

Sorry but I find this really unclear.