What is the slow shutter speed of the camera?

The shooting method is wrong, not a fault.

Because the subject was dark or the light was too dark, if you use the aperture first, then in order to achieve normal exposure, his shutter will slow down to get a normal image. In this case of insufficient light, you can improve your sensitivity to get a normal exposure, so that the shutter speed will not slow down, you can hold on, and the film will not become empty.

If you are not sure in the future, you can use P file, but I can teach you the above methods, change the sensitivity and learn to take flexible photos. I hope it helps you.