Well regarding page speed there are tons of recommendations available, but depending on many different things like for example the amount of plugins installed and the quality of the code, etc.. etc..
My recommendations & checklist is very long, but to be more specific to what you asked and not to complicate things too much, maybe start with:
1) It’s free and simple to use. “WordPress Assets manager, dequeue scripts, dequeue styles”
https://www.ads-software.com/plugins/gonzales/
2) Personally I use this: “Perfmatters” the pro edition.
https://perfmatters.io/features/
Cost: $24.95 per year
3) Not tested yet, but shows a lot of promise: “Flying Scripts by WP Speed Matters”
https://www.ads-software.com/plugins/flying-scripts/
Extra things to look into:
4) And for Cache if you have LiteSpeed server: “LiteSpeed Cache”
https://www.ads-software.com/plugins/litespeed-cache/
5) For images – “WebP Express”
https://www.ads-software.com/plugins/webp-express/
6) “Stop Generating Unnecessary Thumbnails” To stop ALL extra image sizes, because I upload images that are already super optimized, any further changes will make it much bigger and I seen it happen many times.
https://www.ads-software.com/plugins/image-sizes/
More?
*(I’m not affiliated to any of the listed plugins)