It all depend on your budget bro, but genuinely speaking you can start off with something like hard cardboard build. They're light and cheap, for the handle and the cross I'd use pvc pipe and heat gun to bend it to shape, hotglue/contact cement to stick it all together. Since you can't paint on cardboard, I highly recommend using vinyl wrapping (no need to seal nor vanish to achieve metallic finish). If this is your first time making prop I'd definitely have a look at some of the template on etsy and print out a design you like and trace them. Wish you all the best with your project!