This article fits all WordPress themes.
Set cache for your WordPress website
Please set the cache by the WP-Optimize plugin, the free version is enough.
Minify assets files
We use the Autoptimize plugin to minify the CSS and JS files. There is the cache settings in this plugin also, but WP-Optimize is better.
Our suggestion settings:
Please optimize picture capacity, refer to https://seatheme.net/forums/topic/how-to-optimize-image-size/