Practice Makes Good Enough
No matter the amount of tutorials or introductory articles you read, the most reliable way of learning accessibility is practicing it.
You should read and understand the entirety of WCAG 2.2 and apply it where possible. Practice for this really is one of the best learning opportunities, as it deeply engages your thinking about the topic rather than just serving you information that may not be fully memorized.
The goal of accessibility learning isn't knowing every success criterion by number; instead,
it is noting and fixing accessibility issues based on recognition and intuition.