groups – login shortcode

I am looking for additional documentation on how to use the [groups_login] shortcode as I am not sure how to make it work correctly.The documentation on the Implementing it on an access free site it does not show when logged in. When logged out it shows a login form where the user should fill in username and password plus a login button, thats all good. But when trying to set my courser in one of the entry fields I get redirected directly to one of the subcategories of my site without being able to enter username or password.

So far I am using groups only to restrict certain content to particular user groups where needed. All logged out users and logged in users can see the hole website apart from the few sections that are getting restricted to particular groups.

I would be interested in making the whole website only accessible when being registered and logged in. In addition I would restrict certain content sections to user groups who have the necessary permission the way I already do it.