What are some ways I can improve my professional profile outside of work?

Hi, I am a recent college graduate that is currently working in commercial banking as a credit analyst. My current goal is to improve my profile to be competitive in top MBA programs after 4-5 years of experience. I have a 3.94 GPA from a non-target (Finance & Accounting), with multiple leadership experiences in business clubs, fraternities and the CFA research challenge. I have time to do some extracurricular activities on the weekends, but I am unsure on what to focus my efforts on, while pursuing my full time job. I thought about learning a 3rd language, joining a volunteer organization, enrolling in a part time Master's in Project Management, or being a math tutor at my brother's high school.