How to improve my academic vocabulary
I am not quite sure what you mean by "academic vocabulary". If you mean words which appear in your field, read papers in your field or, if their level is too specialized, books for students.

On the other hand, if you mean words like "paper", "rejection", "withdrawal", "paywalled journal" etc., you may want to start at Academia Stack Exchange: reading many questions and answers here gives you a good feeling what academia is about, what certain words mean (and how academics think).