people can only access/see my page at all when logged in with Cern account. How to change that? Is it due to that the page is still in development (how to change the development status?)?
This is due to the CERN dev status module. You can find the settings under Configuration -> CERN dev-status.
But keep in mind: In general the way to publish your website would be to make another official website [in the Web Services] and clone your content to the new website. Test/Development websites should not be visible/accessible for the public.
Hope that helps!