open to any subfield. I've taken introductory micro and macro courses.
The most direct path from high school to being a research economist will probably lead you to taking standard economics courses, and I'm not sure working through the standard curriculum first is the best approach.
Here is a list, heavily biased towards my own field of microeconomics, in roughly increasing order of difficulty, of slightly unconventional books that will provide you with a slightly different perspective. In contrast to most standard undergraduate textbooks, their prices are not obscene either.
Ward Farnsworth, The Legal Analyst: A Toolkit for Thinking about the Law
This is a book that is meant to teach one to think like a law professor. Apparently, that means thinking economically about the law. The book teaches a lot of basic economic reasoning and provides you with examples for this reasoning that you might not encounter in economics courses.
Avinash Dixit and Barry Nalebuff, Thinking Strategically
This is an informal introduction to the most essential ideas of game theory, one of the most, if not the most important tools for theoretical microeconomics.
Itzhak Gilboa, Rational Choice
This book is meant to teach what Gilboa thinks everyone should know about economics, and that is mostly economics enhanced common sense. This is the most direct path to learning to think like an economist and I warmly recommend this book to everyone.
David Friedman, Hidden Order
This fascinating book is an introduction to the standard introductory microeconomics material, disguised as a pop-science book. You will eventually need to balance the author's ideological bias, but the fundamentals are explained quite well.
Martin Osborne and Ariel Rubinstein, Models in Microeconomic Theory
This is an aspirational book and requires a good deal of mathematical sophistication. It basically treats various undergraduate microeconomics topics at a graduate level of rigor. You can download the book for free via Ariel Rubinstein's homepage.
I think as a starting point I would suggest the following books
G. Mankiw: Principles of Microeconomics
This book provides introductory understanding of economics, it is recommended for people studying economics for the first time, without a solid introductory background. It is a very good starting ponit for building intuitions.
G. Mankiw: Principles of Macroeconomics
This book provides introductory understanding of Macroeconomics, it is recommended for people with some basic knowledge microeconomics. The concepts are explained in clearest possible way.
Aplha Chiang: Fundamental Methods of Mathematical Economics
This is probably the most used Maths text book by economics students, it covers most mathematical methods used in various fields of economics, from basic to semi-advanced level. Some basic knowledge of Microeconomics and Macroeconomics maybe required depending on the chapters you read.
Hal Varian: Intermediate Microeconomics (With Calculus)
A very intuitive Intermediate Microeconomics text books, it covers many fields such as Consumer Theory, Producer Theory, Game Theory, Managerial economics, General Equilibrium.
Olivier Blanchard: Macroeconomics
A very intuitive Intermediate Macroeconomics text books, it covers most intermediate topics in Macroeconomic.
William Greene: Econometric Analysis
This is an introductory text book in econometrics, recommended if you want to be a researcher in economics, prior knowledge of stats, maths, micro & macro economics is recommended.
Hal Varian: Microeconomics Analysis
This is for more ambitious students, I would not recommend reading this unless you master the equivalent topic in book 3 and 4.
Depending on your level you may need to jump from one already, if you have a solid introductory you can jump to 3 and 4
If you master 3 and 4, you have an open door to be successful.