I am currently trying to learn how to manually improve a WordPress-based site without having to use any plugins. Or, at least, minimize the use of them. So, I am diving into the exciting world of HTML, CSS, and JS but, NOT to be able to build and develop WordPress sites from scratch but to be able to read through the code and know what to look for.
During this learning process, I´ve found a few youtube tutorials that have helped me a lot to understand what to look for and how to approach this process.
Improving Load Performance - Chrome DevTools 101
Speed Up WordPress in 2019: How To Optimize Your Website & Make It Load Fast
Optimize your code: load code at the right time
Load your page faster: remove unused code
And, if you´re using Elementor on your sites, I highly recommend you watch
these tutorials from the SproutedWeb YouTube Channel.
On a side and more personal note, I found a site that offers a free download of this Udemy course...
Our A - Z Performance Blueprint to Make Your WordPress Site Not Just Fast, But One of the Fastest Sites On Earth!
www.udemy.com
But, in order to download it is through a torrent file and my internet connection is NOT fast enough in order to download it. In fact, it would take me 5+ days to download it.
So, if you´re interested, I can send you the torrent file through PM and perhaps you can upload it to Mega and share the link with me?
Let me know!