Hello, first of all, you should consider if those optimizations are worth your time and effort, is there any other action that could improve your website that requires less effort?

I recommend asking these questions to yourself, after that if you still want to improve your website performance metrics, you should try a cache plugin or a JS and CSS minify plugin. For example WP Rocket.

Also, I highly recommend you to hire expert services, this can save you tons of time and effort. For example: This digital marketing agency in The San Francisco Bay Area.