What textbook can I use to really understand microeconomics, macroeconomics and mathematical economics What textbook can I use to really understand microeconomics, macroeconomics and mathematical economics. It can be different textbooks. I'm in first year college taking introductory courses in microeconomics, macroeconomics and mathematical economics. I need a really good textbook or online site to understand what I'm studying well. I like the way people on this site answer and explain questions with application. I want to be like that too. I have Greg mankiw books by the way, I have schaum's introduction to mathematical economics. I need to read more quality books to understand.

Thanks
Your question is quite broad, but here are a couple of (open) book sites you might get started with:
https://open.umn.edu/opentextbooks/SearchResults.aspx?subjectAreaId=4
http://www.freebookcentre.net/Business/Economics-Books.html

When you're familiar with the basics, you might ask the question again with a more specific topic you'd like to study.

Expertise on economics (or pretty much any academic subject) is gained through years of studying and thought. It's, at least to me, a fascinating way of thinking about the world.