Okay please make sure that envato market plugin is deactivated in your setup .
if not then please deactivate it .It is having some issues with current version of wordpress .
refer this tip to deactivate it :
https://www.ostraining.com/blog/wordpress/disable-a-wordpress-plugin/
Second step is to install this plugin "query monitor"
refer this tip to know which plugin is actually putting load on your server :
https://kinsta.com/blog/query-monitor/
Using caching techniques like memcached, opcache on server side might improve some speed .
Also try switching to php version 7.0 (not 7.1 ,its unstable and is not compatible with theme ) .
Deactivate plugins that you dont feel necessary
Please also try disabling touch points if you have enabled them from wp-admin -> lms -> setitngs -> touch points .