Just so you know, on this forum if you're asking about a specific prop or costume it's expected that you post a reference picture with it. That said, I would suggest foam for the head. Lowes and Home Depot sell pink or blue insulation foam sheets in various thicknesses. Get a sheet of one of the thinner ones, no more than an inch I would say. That will give you plenty of material to work with. Get lots of ref pics together and draw out a template either on your comp or by hand, don't just try to cut out the design from the foam freehand. If you use the search tool in this forum there's a ton of threads on how to cut, sand, and paint insulation foam. For the red circle I would try to find a random object you could paint, like a plastic toy ball or something similar. Keep your eyes out at yard sales and in the craft store and you might find the perfect thing.
As for the staff, I do know that pvc pipe at that length and thickness will tend to bend and be wobbly on its own. Either use wood or use pvc with a wooden dowel inside of it for support. Have fun, this is a great classic costume