Cleaners such as Windex or 409 will harm your new piece of acrylic. Use Lemon Pledge or Bold.  Never use a dry cloth or your hand to clean your acrylic! This rubs the dirt and dust INTO the acrylic as much as it rubs it OFF. First, blow the dust or dirt off, or use water and a soft cloth to float the dirt off. Then use a mild solution of dish detergent and warm water.