Aperture is how much light gets in the lens, Shutter speed is how fast the shutter is and ISO is the light sensitivity. You would need to change the ISO when it get’s too dark or too bright whether it’s inside or outside. Aperture and shutter priority settings helps adjusts on it’s own while you only have to worry about the ISO. There are 3 types of AF modes to fit your shooting situation which is One Shot AF, AI Servo AF, and AI Focus. It is also important to meter the light well because it will adjust the light on the subject. White balance is the temperature lighting and you need to adjust it so that it wouldn’t have too much warm or cold tone. Depth of field focuses on the subject but the background would be blurry. Drive modes does all the work for you since it would adjust the aperture, shutter speed and ISO. Your camera’s exposure compensation is something you can adjust with the exposure based on the brightest reflected light from a scene.