Everyone learns differently so it's hard to generalise. It seems for you it could be more efficient to "learn by doing". For example start some simple project and then gradually add more advanced topics (there are many websites with ideas for such beginner projects).

If stuck try to find answer by yourself googling, read documentation/books or seek for help from community. I think it's more efficient and entertaining than reading whole books chapter by chapter before starting using knowledge.

If you must learn something quickly I would probably search advice from a person who already knows what is important to learn first or search if someone resolved similar problem.

That way you will learn just needed subset for a beginning to resolve a problem and then you can learn more.