Videos are a good exposure, but practice with donor boards are the best.  Watching is fine, but you need to spend time trying to change components.  Something as simple as removing a component off of a board and reinstalling it will be the best.  Next, take in a failed unit and try to fix it.  Follow the diagnostic path shown on many videos to locate the problem and replace components as needed.  You will likely fail many times at first, but will eventually succeed.  Don't get discouraged. You can get formal electronics training at a local college too if you wish to pursue this as a career.  Start small and spend the time to get real experience in all aspects of the repair cycle.  This includes not only diagnosis with parts replacement, but also dealing with customers and managing a business.

Start part time where you are not dependent upon the income from this if you can.  That will relieve some of the pressure to get things done and allow you to make mistakes and recover from them.  You will learn much from making mistakes.

Dan

ABR Services