It gets very detailed but the explanations are overall excellent. You may find yourself looking for explanations for things within the explanation. However, for the sake of full disclosure, I sometimes have to do much the same. Lots going on and always lots more to learn.
And you may be able to find an older copy in a used book store or somewhere like Goodwill stores that carry books. Older editions will provide quite a bit of the basics. Plus you may be able to check out a copy via your local library. In fact any IT/Computer Science books will have some value for you. Not unusual to need to read two or three explanations to grasp the overall topic and achieve some level of understanding.
If there is a college nearby you may be able to pick up a few intro level books. Professors and instructors often get complimentary copies of books to review. Maybe you could find someone who is willing to give up extra copies. Or the book store may have discounted used text books for sale.
Plus there are many online tutorials - some very good one's in this forum.
Check out the "How To Geek" - he does some excellent tutorials ( www.howtogeek.com).
And keep doing hands on work. Pick up old computers whenevery you can to work on and experiment with. Once people know you are looking for such things you can quickly end up with a pile of stuff. Saves the landfills if there is no recycling centers around.
Lots of fun but get outside also. Keep up with your people skills and school classes. Writing, communications, math, and science will serve you well.