Generally speaking, learning to be a chef is not necessary, and you can learn it at the age of 12. How long it takes to learn to be a chef is actually chosen according to the students' own needs. If you are interested, learning Chinese food is only for the needs of daily life. It is enough to choose a short-term crash course. If you want to have a high-income and stable job, it is more appropriate to choose a long-term major, because after a long period of continuous practice.