This question will probably be closed, as the information has been covered numerous times already and is not specific to any camera, but before it is:
The combination of aperture, shutter speed and ISO taken together will determine the correct exposure for a picture. What that "correct exposure" will be varies from picture to picture, and depends on the amount of light falling on the scene, the content of the scene, and your artistic intent.
The aperture controls both the rate at which light enters the camera and how much of the image will be in focus (depth of field). Larger apertures (smaller f-numbers) let in more light, but reduce the depth of field. Smaller apertures let in less light, but more of the image will be in focus.
The shutter speed controls how long light will enter the camera, and also how much or how little movement will be captured. It doesn't matter whether that movement is you moving the camera or your subject moving. You may want to freeze one or both of those, or you may have artistic reasons for allowing one or both of those to blur. And the longer the focal length of the lens, the less movement -- of the camera or the subject -- is needed to produce blur, so the higher the shutter speed would have to be to freeze motion.
The ISO setting controls the apparent sensitivity of the camera to light. (That's not exactly true, but it's close enough to be worth thinking about in those terms.) Increasing the ISO value reduces the amount of light you need to arrive at a "correct" exposure, but it comes at the cost of increasing noise and reducing dynamic range.
Ideally you would like to keep the ISO setting as low as possible, but that may mean having to use a wider aperture (losing apparent focus in parts of the image you want to be in focus) or a slower shutter speed (allowing either the camera or the subject to move during the exposure), or worse, both.
Ordinarily, one of either the shutter speed or the aperture will be especially important for the picture you are trying to make. Occasionally, it will be both that are critical, but there is often more freedom in choosing an appropriate value of the less-important of the two. When that combination of shutter speed and aperture cannot let enough light into the camera to arrive at the exposure you desire, you have to raise the ISO so that less light is required to make a good exposure. While raising the ISO will increase noise somewhat and reduce dynamic range somewhat, it does far less damage to the final image than trying to make a picture brighter in later processing (post-processing).
Unless you are shooting exactly the same thing under exactly the same lighting all of the time, there is no one best setting.