It's hard to say how long it will take to learn. Everyone has different qualifications and spends different time every day. Three days of fishing and two days of drying nets may still be in the initial stage of life. If you study hard, you can get started in two to three months, starting with simple learning, such as Mitsubishi fx series or Siemens 200. After learning, the most important thing is to practice. You can buy a plc and practice more cases. Don't worry about these small cases of traffic lights in the early stage.