Whether shooting in the dark. To get a sharp image, use the more closed off to the aperture. The higher f-number, the less light can come over the lens hole. Set value to f13, f16 or even more: f22 or f32. Moon is moving object, so you can’t wait too long, you don’t want to get blurry image. For start try settings: f16 ISO200 shutter speed 1/200 if the sky is bright, or f8 ISO200 shutter 1/125. Moon is very bright, there is risk, image can be overexposed, you can underexpose image by half (1/2) or one stop (1). There are no fixed correct values, moon luminosity different: because of phase, place in the sky.