This article will explain how you can optimize Directory box Theme. Here are simple instructions to do that
Following are the recommendations if your site speed is slow.
1. Reduce the size of images.
2. Use WordPress cache plugin i-e WP super cache.
3. Choose best hosting service for your website.
4. Remove Unused Plugins
You can analyze your site page speed at: https://developers.google.com/speed/pagespeed/insights/