1, it is not too late to learn robots at the age of 30. After all, you are a truly trained person, but you have been put on hold for a long time. If you put your heart into it, your technical level will improve quickly.
2. The robot is composed of several parts: mechanical part (mechanical principle and courses of mechanical part in school), motion executive parts (produced by professional manufacturers) and software program control part (this is a difficult point, but there is specialization in the technical field).
3. Robot motion is mainly realized by electric, pneumatic or hydraulic means (except mechanical parts). It is suggested to find some product samples (moving parts samples) from manufacturers first, and consider the training materials of SMC company. Their samples all contain instructions on maintenance and action principles, so that you can get started quickly (because you already have the knowledge you learned in school), but whether you can get these materials depends on yourself.