I don’t know how your specific roasted coffee grinder adjusts but you should start with a medium grind. If the coffee is too weak make the grind finer and check the temperature of your water which should be about  190-195 degrees. If too strong use a coarser grind. Feel the grind with your fingers if it feels like white sugar it is perfect for espresso but too fine for pour overs, French Press or Drip. Grind is usually a matter of personal preference.  Too fine and the water will over extract and the coffee more bitter. You are shooting for maximum flavor, sweetness and mouthfeel without over extraction.