This theme comes with a couple of plugin support. Only activate plugins that you need. Deactivate unused plugins.
We recommend using a good caching plugin as well as a script optimize plugin. It will decrease loading time.
You can try these plugins –
- https://wordpress.org/plugins/wp-super-cache/
- https://wordpress.org/plugins/autoptimize/
- https://wordpress.org/plugins/wp-smushit/
- https://wordpress.org/plugins/wp-sweep/
You can check this detailed tutorial – http://www.wpbeginner.com/wordpress-performance-speed/