How can I become a translator?

My goal is to become an interpreter. I speak English, Spanish, Creole and French is my mother tongue. I am planning on doing my B.A in Translation in French, English and Spanish and afterwords I would like to complete a Masters in Conference Interpretation. In order to get in, I need to write an admission exams. How can I improve my grammar, written and speaking skills in French, English and Creole so that I can achieve my goal? And what should one do if he or she wants to prepare themselves before getting into this field professionally?How can I become a translator?
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