Beginner question: ISO
Take the camera out of auto ISO . Raising the ISO is equivalent to letting in more light to the lens, just as a slower shutter speed or larger aperture will. Leave it somewhere between 100 & 400. This will give you a good shutter speed in general conditions. If you're in low light/cloud just bump it up to adjust your aperture or shutter sped (depending on what mode you are in ). If shooting in aperture mode the higher the ISO the faster the shutter speed will be. If in shutter mode increasing the ISO will give you a smaller aperture. Understanding the Exposure Triangle ( Shutter/Aperture/ISO ) will help you in your settings. I generally shoot in aperture mode ( AV on Canon ) and then adjust the ISO depending on what shutter speed I need. Landscapes on a tripod would be 100 but on a windy day I may increase the ISO to get a faster shutter speed to eliminate movement in branches etc. generally if hand holding a lens I will bump up the ISO to eliminate camera shake. The above is based on a fixed exposure compensation so if you adjust exposure compensation it will also have an effect on your settings.