I am new to camping and just got a 1997 Camplite by Damon pop-up. It has 2 end slide outs and a side slide out. Everything seems to be in good shape with the exception of some mildew on some of the canvas. How can I clean it? Do I treat the canvas with anything for waterproofing or mildew resistance after cleaning? What else should I do to make sure the trailer is ready for use?