Good photography courses will teach about gesture and light.    Many times to capture gesture you learn to anticipate, have your camera at the ready and have a DSLR camera with a fast motor drive.   Again, carrying a camera in a camera bag will slow your ability and desire to capture something that grabs your eye.  Stay ready with your camera on your shoulder. Find a camera and lens combination that is comfortable for you to carry. I like my Fuji X-E1