Could I ask real quick why you dislike W3Schools? I def learned SQL syntax and basic HTML/CSS (I needed to use CSS selectors but had basically no knowledge) through them and actually thought to myself they did a great job at keeping things need-to-know for immediate use.

I have a feeling I know your answer - as a financial professional I initially used Investopedia in a pinch but over the years realized their accuracy has an inverse relation with the specificity of the topic. After seeing incorrect formulas and descriptions a handful of times, I eventually stopped using it completely.