The cinematographer is also often referred to as the director of photography (DP). You’re in charge of how the camera moves. How the lighting is set up. What angles are used, and more.
Your job is not to direct actors, get in the way of camera operators who are not you, tell the sound department how to set up sound, etc.
If you want to be successful as a cinematographer, you’ll need to learn the ins and outs of filming and where you belong.