The IT world (and the world in general) is changing very fast.
It is quite unlikely that you will be able to make a career out of building computers.
There may be more opportunities involving networking, IoT, 3D printing, robotics, communications, security, etc. Difficult to predict.
Not easy for anyone these days. I do not intend to be discouraging - be great if you can prove me wrong. But we must be realistic.
As for jobs and potential employers - the answer is that you must read the "Help Wanted" ads and go online and search for positions. And you must learn what skills and experience levels employers are looking for.
But after that there is so much more involved.... Boils down to convincing a potential employer that you can do the job and be a solid, reliable, team player, with good work ethics. And honest.
Starting out means that you will be working in the lowest trenches with the dullest assignments - helpdesk is common. How far up and how fast you can move up depends on your ablility, skills, willingness to sacrifice, etc.. And some luck as well.
Go to a college (two year is fine) or vocational institution and learn about the programs they offer.
(Note: Be careful about for profit technical schools that guarantee employment. Research them carefully.)
Keep your options open by taking classes. Not just technical classes. You need to be able to write, to communicate, to work with people at all levels, and in general be cognizant of the bigger picture. Find a mentor. Be willing to work hard and continue to learn. Your path will become clearer.