☝️ By default, you look at your scene (Viewport) through the personal camera. You can add a new camera object. The last added camera will be used for the play mode.
☝️You can lock the camera layer to protect your camera angle.
☝️ You can animate a camera object.
☝️You can add objects inside the camera layer so they will look fixed in the space.
☝️ If you work with an added camera in your project, occasionally check which camera is selected for the Viewport and Play mode.