Articles and Professions

I'm super confused about when to put an indefinite article before a noun like dancer, skater, singer. I know you are never supposed to use it when speaking about your profession. Je suis chanteuse. But, what if you are talking about a student. Il est élève? Is student a profession and what if that student does extracurriculars like ice skating? Il est un patineur sur glace or Il est patineur sur glace. How do you say you are a student but you are also a singer or a soccer player or a swimmer.