I want to replace a Switch/Receptacle with a dimmer switch. The switch/receptacle is wired with 2 black,1 white, and a ground. The new dimmer has a black, a red, and a ground. Obviously the ground goes to the ground but what do I do from here. It is a single pole light .

Put a wire nut on the white, connect one black wire to the black wire of the dimmer, connect other black wire to the red of the dimmer.