featured image on post

Hello,

You can do this in the free theme. Set the post format to image, as seen here:
http://docs.kadencethemes.com/ascend-free/blog-posts/blog-post-image/

And then assign the featured image. the “head content” setting will determine how the image appears.

Let me know if that works for you!

-Kevin

This plugin should be able to take care of that for you:
https://wordpress.org/plugins/bulk-convert-post-format/

Let me know if that works!

-Kevin