I am a junior in high school and throughout my life I have always had a fascination with space. I use to watch "Space's Deepest secrets" and stuff like that but after a while I stopped learning much and became bored. Then I took an astronomy class in sophomore year which was fun until it ended. After that there wasn't much for me to do, but now I want to go from the beginning to the end. I want to learn and everything I can all over again, but this time I want to go farther. This is where my problem comes from, I have absolutely no idea where to start and would really appreciate any help that could be given.
This question is very general/broad and there is no clear answer possible (neither is there a single good way to start learning Astrophysics) so you will get a lot of subjective answers. I imagine that it may not be the typical Q&A style on this platform. But anyway, here's my subjective answer:
The first book that comes to my mind is:
The Anthropic Cosmological Principle by John D. Barrow and Frank J. Tipler
This is the highest level astronomy book that I read during middle/high school and made me decide to study astronomy. It is relatively easy to follow the physics and it has a nice story in the background (the anthropic principle) which makes it a page turner
My introductionary freshman's University book
An Introduction to Modern Astrophysics by Bradley W. Carroll and Dale A. Ostlie
This contains the basic stuff. It is easy to read and covers a broad range of topics.
What helped me understand relativity, but I imagine it is a great source for much other science topics:
Feynman Lectures by Richard Feynman
When I did not understand my course note the story from Feynman helped me through it. I actually only read the special relativity part when I needed to pass my examy, but it covers a much larger range (it is a shame I have still not read the rest while that chapter about relativity had such great impact).
Understanding quantum mechanics was much more difficult for me than relativity. I had to pass the barrier of accepting the principle rather than keep challenging it.
Introduction to Quantum Mechanics by David J. Griffiths
This is a very standard introductory text. Clearly written with simple mathematics.
Inleiding tot de golvings- en de quantum-mechanica by Adriaan D. Fokker
I like reading old-fashioned stuff. It keeps me stick to the hard facts and potentionally makes me understand better why, but espescially how, we got to construct the theoretic ideas (This particular one is hard to find; another more available good classic is Ernst Mach's the science of mechanics).
This work is an early description of the application of wave-mechanics. You can sort of see the birth of the idea of quantum mechanics
Nice works to read:
There must be as many books as stars? This is one of those books. I got it from some second-hand store. This sort of stuff is what keeps me connected to astronomy after quitting my studies in astronomy.
I like to read in it since it covers a wide range of topics and is not too much in-depth. It is pretty old and a bunch of articles, but it is nice to read from this moment in time (I hate it that I can not set back the clock on the internet and get an old snapshot from it. We have the wayback archive but it isn't working sufficiently to generate an old snapshot).
Introduction to cosmology J.V. Narlikar
.... to be continued
Stuff on relativity
Space - Time - Matter Paul S. Wesson
Spacetime and Singularities an Introduction Gregory L. Naber
.... to be continued
Some other stuff that worked on me
Hydrodynamic and Hydromagnetic Stability by Subrahmanyan Chandrasekhar
This was my reference work for my Bsc thesis
an amateur radio telescope by George W. Swenson
When I was a teenager I though I could easily make a radio telescope (not).