Activity for Mirrrcast

I go in a few weeks for my first fitting, and I just like to be prepared for things this may be a silly question, but I know absolutely nothing about a bustle besides there are different types. With that being said, is this something the seamstress...

I was told to register for my bridal shower. Where can I do this at? I have read many different things. Some stating the wedding registry is used for a bridal shower, and then I read on The Knot that the purpose is to "shower the bride" with gifts...