Hi Syabab,
We no longer have the file default.guests.php in ES2.0.
The easiest way would be to enable the lockdown mode. That way, guest users will have to login first before trying to load any part of the site.
Settings>General>General>Enable Lockdown

Hi,

In lockdown mode, when user want to 'Social Share' their status, stream in Facebook will show 'Login to the site' instead of the correct status.

Is there a way to share post from Easysocial to Facebook correctly in lockdown mode?

Also in lockdown mode, url will add 'login' at the end, different if not in lockdown mode.

Hey Syabab,
Since you want Facebook to crawl the site, then we cannot use lockdown mode.
Instead, perhaps you can try creating a new EasySocial Login Layout menu item that is visible on the site.
Then, place the EasySocial dashboard menu item that you have under a hidden menu(not visible to guest users). http://take.ms/RD39c

This way, since the EasySocial dashboard item is not visible on the frontpage, users will have to login first to access EasySocial pages.