On the bottom of the create page there is a button to turn on social media. Where do I add the links to configure twitter, google, facebook and linkdin?
I believe key here is that what CiviCRM inserts are social media 'shares' - not social media 'links' or 'follow us'.
for social media links we add https://www.drupal.org/project/social_media_links (I'm sure in wordpress land there are plugins that work exactly like this drupal module).
Social media links behave as you asked in your question: you must configure which icons you want and add their targets (links to them). These targets typically are your twitter feed; your linkedin page; your etc.
Turning 'on' the social network links provides buttons so that the user can use their FB etc accounts to share the Event/Contribution Page.
I.e if you click on the Tweet it will open up twitter.com, and requires you to login in to your twitter account if the user is not already logged in.
Having said that, I thought I would confirm on demo site but even with the "allow sharing" turned on, no links show on the Event page but it would make sense for it to be suppressed on the demo sites I guess.