1. Select a diving training institution. First of all, it is very important to choose a suitable diving training institution. PADI is a popular diving certification body. You can search "PADI" for more information.

2. Theoretical study. Theoretical study includes diving physics, diving medicine and diving equipment. This can be achieved by video and electronic materials provided by diving training institutions or by attending face-to-face courses.

3. Physical fitness test and theoretical examination. After theoretical study, physical fitness test and theoretical examination are usually needed. These tests and exams assess your physical fitness and diving ability.

4. Training in calm waters. Still water training is conducted in swimming pools or simulated sea areas, aiming at teaching divers how to dive safely and how to use diving equipment.

5. Open water diving training. After mastering the basic skills, you will conduct diving training in open waters under the guidance of a coach. This usually involves multiple dives to adapt to the actual diving environment.

6. Practical operation test. After completing all the necessary training and exams, you will take the practical operation exam. This includes underwater diving and safety drills.