I recommend intelligent qigong, which is a kind of health qigong. I know not only why, but also why. It has a complete and effective theoretical system and method, and can learn a high level without the help of a master. Please search "Tong Ling Station" for details. The information on it is very complete. If you want to get started, please download Concise Intelligent Qigong first. From the point to the surface, you can hold your breath through the top, learn by yourself with three hearts, and practice your breath for three months. If your constitution is sensitive, you should feel angry soon by practicing the method of holding your breath.
Look at the friendship link in Tong Ling Station. There is a Qigong cancer prevention station. Teacher Zhou is in Shenzhen.