I would strongly recommend reading Data-Oriented Programming in Java by Chris Kiehl [1]. Chris introduces you to the data-oriented thinking through a series of super basic examples, gradually making things more interesting. He leverages the latest Java features (e.g. record classes) to illustrate the ideas and explains why these features are important. I don't know him personally, but we both work at AWS. I liked the book so much, that I reached out internally thanking him for writing the book.

[1] https://www.manning.com/books/data-oriented-programming-in-j...