speed up wordpress website

Hello guys,
Hope someone can help me speed up my WordPress site.
I've tried most of the popular plugins to fix the issues we're having with Page Speed Insight.
These plugins I tried were like w3 total cache and autoptimize,
Unfortunately, some of them did not make any noticeable change, and others led to the suspension of some features on my site.
Honestly, I don't like using these plugins, I prefer to fix these problems manually, but unfortunately I don't know where to start and I haven't...

speed up wordpress website WordPress ...