Hello,

1. Here is an article with an instruction to solve similar issue http://www.wpbeginner.com/wp-tutorials/how-to-fix-facebook-incorrect-thumbnail-issue-in-wordpress/

2. There are two kinds of social buttons in our theme: share and follow. Currently, you have “share” type that allows your visitors to share your website in social networks. You can simply change it to “follow” and specify your social profile links in Theme Settings -> Social.

Regards