Where can I learn the design knowledge of complete sets of electrical equipment (my family is poor and I can't afford to go to college)

Hehe, why do you want to learn electrical complete design? This apprentice can't learn. It's best to find an electrical company to do the design and learn from the master (you can practice while working). General companies recruit at least junior college or electrical majors. If you have a relative who is a leader in an electric company, you can ask him to introduce you.