Confirmation advice please?

my boyfriends confirmation is in about a week. first off, what is it? 0.0 they go to an episcopal church and i go with them sometimes. also, what should i wear? is a dress too fancy? i had this one in mind http://www.kohls.com/kohlsStore/juniors/dressesanddressyapparel/dresses/PRD~800580/Candies+Emma+Colorblock+Tiered+Dress.jsp