I rarely wash my fabric but will sometimes if it is red. I've never had any problems.
Color catchers are in the laundry aisle and come in a box. I usually find them on the top shelf. There are several different brands but some stores only carry one. Shout is one brand but there are others. I have used different brands and they all seem to work equally as well.
Freezer paper is usually in with the foil and plastic wrap area of the store but I have also found it in some stores where the measuring spoons and kitchen utensils and odds and ends of dishes are.