Site very slow / won't load

Slowness/high CPU usage could be due to (but not limited to):
– a poor or memory intensive theme
– poor or memory intensive plugins – your server is slow (e.g., “process hang”, overload, other problems, etc.)
Start with reading this article (and follow the links):
– https://www.wptavern.com/determining-which-plugins-are-slowing-your-site-down
– https://wordpress.stackexchange.com/questions/656/is-there-a-way-to-measure-server-resource-cpu-usage-by-wp-plugins/799#799
– also view this WP tv tutorial: https://wordpress.tv/2013/02/28/vinay-paudel-optimizing-and-speeding-up-a-wordpress-site/