How Many Times Should The Face Be Washed To Cure Acne?

Hi I'm 18 years old. I weigh 108lbs, and I am 5'5". I have acne issues on my forehead, nose, and chin. I have the most acne issue on my forehead. I would like to know how many times I should wash my face. My face gets extremely greasy during the day, but I heard that you should cleanse your face at least twice a day. And I would like to know if cetaphil is a good night or daytime cleanser.