Yes, you can say “My occupation is a student” to describe what you do. However, it’s worth noting that “occupation” typically refers to one’s profession or job, whereas being a student is usually considered a temporary role or status rather than a long-term occupation.
If you’re filling out a form or providing information for a more formal context, it might be more appropriate to use the term “student” or “learner” under a different category, such as “current role” or “current status”.