As a student of knowledge, I face many crisis on this path especially on my purpose in learning. I am confused, can I aspire to become Ayatollah or a marja as a student and if not what should be the correct purpose

The ultimate purpose is to serve Allah with full sincerity. Now this service comes in many forms. If you have the interest to become a scholar for the sake of Allah, and to be a source of guidance for people, then that’s wonderful. Go for it.