Reddit mentions of The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory

Lots of books about astronomy and astrophysics for laypeople.
Cosmos
A Brief History of Time
The Elegant Universe
Welcome to the Universe
(I haven't read the last one. Stumbled on it looking up the Amazon links for the others, but it looks pretty cool, to me.)

Take all the math and science courses you can, especially if your high school offers AP physics and calculus.

A Brief History of Time, by Stephen Hawking

-- This is the first book I thought of when I saw your title. It might be the most popular pop-science book of all time. And -- especially how dry and complicated the subject seems -- it's very clear and entertaining.

A Briefer History of Time, by Stephen Hawking.

The Universe in a Nutshell, by Stephen Hawking.

The Elegant Universe, by Brian Greene.

The Fabric of the Cosmos: Space, Time, and the Texture of Reality, by Brian Greene.

These are books about physics (the way the world works), astrophysics (the way the universe works on a gigantic scale), and quantum physics (the way the world works on the tiniest scale).

I know. It sounds incredibly boring and complicated. And it is complicated. There's a quote widely attributed to a physicist named Richard Feynman: "If you think you understand quantum physics, you don't understand quantum physics." But that's what's so amazing about it. It's so weird. It's often so counter-intuitive to how we think the world and science works. You'll read about how time slows down as you approach the speed of light, or about the double slit experiment, and put the book down and think, "That's crazy. The world can't actually work like that.

These books do an amazing job of explaining incredibly complicated concepts, without using any math or equations. By the end of any of these books, you're going to understand some very complicated concepts that will probably change the way you see the world.