There’s a book that I’ve gone through several times over the past 6 years called Amazon.com: Professional WordPress Plugin Development eBook: Brad Williams, Ozh Richard, Justin Tadlock: Kindle Store .
Both Brad, Ozh, and Justin are reputable and knowledgeable fellows with tons of expertise in the WordPress field.
Since it goes over the WordPress life cycle in depth and focuses on best practices while building scalable plugins on top of WordPress, I would suggest some practical background in PHP development from scratch and basic experience building small and simple plugins. Beginner WordPress development and plugin development courses are available in most educational portals and networks (including YouTube).
But “Professional WordPress Plugin Development” is definitely the pro league for all things plugin development. Later on you can specialize in different areas and APIs that weren’t available back when the book was written, such as Ebook: The Ultimate Guide to the WordPress Rest API.
