I have found that most water based paints will work well, but I especially like working with acrylic. I usually use a base coat, like gesso, to seal the surface and often use textured acrylic based products and finally, seal with an acrylic, clear varnish, often 5-7 layers of acrylic are built up.........for performance masks, I think it's more important to add many layers to strengthen them......... There are many brands and types of acrylic paint, depending on which part of the world you are in.
There is no right way to paint papier mache........whatever works best and is readily available to you, many artists use many different techniques.......