WP Rocket is a plugin cache and load optimization. It has a very simple and intuitive use, so you can make many optimizations. Among other options, it allows you to apply cache to WordPress templates and their mobile versions. It allows the caching of fonts, css, js or jquery files, considerably reducing web load times.
Preloading fonts, sitemap or lazy loading of images will make your website fly.
However, it is not a simple plugin and requires some skill to configure it correctly without failures in other areas of the web.