Wordpress Mixed Content Error (google font related)
Find the link for 'http://fonts.googleapis.com/css?family=Oswald:300,400,700 in your theme's functions.php file or header.php and do one of two things:
1) add an s to http, and Google will serve the font via https
or
2), remove the http: to make the link protocol agnostic, i.e. //fonts.googleapis.com/css?family=Oswald:300,400,700 This is the best method for compatibility in all cases.
Either way, that will solve the mixed content errors.
But, still learn how to use developer tools - the most basic tools for any web development - to check all loaded resources and find any others that are loading non-https, such as image links, etc. Use the developer tools in Firefox (or Firebug) or Chrome or Safari or IE.