Complex sentence: Europa Cup, at the "Krasnoe Ozero" in the suburb of Saint-Petersburg, was her first start, where she was 21st in mogul and 18th in dual mogul.
Split into simpler sentences: Europa Cup, at the "Krasnoe Ozero" in the suburb of Saint-Petersburg, was her first start. She was 21st in mogul and 18th in dual mogul.