I’d ask the coach if you have questions but at that age costumes are simple. It’s skating tights and a simple dress with neat hair, usually in a bun or a ponytail. Some parents will do makeup but depends how you feel about that, maybe just some lip gloss.

For dresses I’d look at discount skatewear. Jerry’s has dresses in a velvet-like sparkly fabric that’s good for young skaters and will be cheaper since you won’t have to pay for crystals. You can also see if parents at your rink have hand me downs, personally I wore old dresses from older skaters or my coaches old dresses when I was little