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...