depends. i'm assuming this is a university, and each one has their own "returning students" policies. mine i think will allow me to return smoothly (i'm a student but i haven't enrolled in any courses for the last year), but it might be different since you haven't taken classes there yet. chances are, if you have a student account already set up, you might be okay.
+1 for talk with an advisor, they'll help you out OP