There are 2 sides to the industry. Hardware and software. Even if you get into software it's nice to know hardware, so maybe learn hardware.
Depending on your current knowledge maybe pick up the book "Upgrading and Repairing PCs" or borrow it from a local library. The ebook is available for $35. Once you know the hardware you could even study and pass the simple A+ certification before high school graduation. This will learn you the basics at a young age. In the future you could get into the Server side of things and IT side with routers etc.... Get into the Cisco programming end of hardware for networking. But at the very least you want a master knowledge of PC repair and be able to build custom open loop liquid cooling, overclock systems, etc.... Just know your PC inside out. It's not difficult. Even if you don't work with hardware, it's nice to know it for your own use if you work in other areas such as programming.
Next you have software. Programming. At the very least you want to know windows pretty good. So picking up a book to learn Windows 10 inside out is a good idea. You may even want to start learning Linux since a lot of the web runs off linux, apache, PHP, MySQL, etc.... Just get used to these 2 operating systems beyond a basic user level. The next step if you choose as a career would be to learn the server side of Windows and Linux to become an IT administrator. You could then Study Windows Server and write your MCSA certification.
Now figure out what you want to do if anything at a software level. Do you want to become a programmer and start making apps, databases, websites? Go to University and study computer science? Become a gaming programmer? It would be good to learn websites and get into HTML and wordpress and Adobe. An extension of basic HTML websites is to get into database programming and interface databases with websites. There is much opportunity if you can master this and make functional websites and databases. Databases would be learning Oracle, SQL (Microsoft/Windows), and MySQL (Open Source/Linux). This can lead you into learning PHP and other programming languages. The ultimate step would be to get your degree in Computer Science after graduation.
So to summarize.
- Learn the PC hardware and have fun. Maybe upgrade your own computer at home. Build a custom open loop liquid cooler with rigid pipes. A fancy case, etc.... Have fun with it. If you are serious about it, study for the simple A+ certification and write that. It's a pretty basic and stupid cert, but hey why not.
- Next learn Windows 10 inside out. Get a book and go through it.
- If you want to get into programming apps, websites, databases, etc... I'd try to learn Linux. You can install Linux for free on your computer and start learning it. Pick up a book on Linux and start learning it.
- If you want to do websites pick up an up to date 2017/2018 book on HTML website programming and start making websites. Knowing linux will help you with the server end of the website business and apache. Most websites are made with wordpress so learn this. It's free and fun. Make a personal website, maybe even volunteer and make a website for some local business or non-profits around town. This would be sites you can add to your resume.
- An extension of website programming is databases and interfacing it with websites. That mean SQL and MySQL. I'd start with MySQL which is more popular and free. If you can master this you can go to college and study database programming and make it a career. Knowing databases allows you to make very useful websites for business and the website authoring can become a career. Maybe do database professionally and websites on the side as a business hobby.
- One step further is getting into apps. Mobile apps, and extensions for websites. Pearl, PHP, Python, etc... Programming languages like these. Add this to your website, database repertoire and you are starting to become a master. If you can master all 3 you can become self employed making websites, apps, mobile apps and websites, and databases for businesses.
- Another totally different path of the software side is your traditional programming. Languages like C++ for example. This is where you go to University to study computer science and get into traditional programming.
But as mentioned before. Learn the PC hardware and maybe turn old systems into functional ones and donate them to local charities, etc... Maybe turn old systems into a freeNAS machine and learn that. On the software side learn HTML and get into website programming. As you get better learn database programming and maybe offer to do a free website for a business or 2 or a non-profit to build a resume and experience. Take it from there with 3 possible routes. IT administration (Windows Server, Cisco router programming), Website/database programming (MySQL, Python, PHP, etc...), Computer Science programmer (C++).
The only other area untouch is making the actual hardware which would be electronics/computer engineering at university.