Good job on your GMAT, first off!
For your work experience, be sure to focus on what you've achieved with your various positions. It's difficult to say what business schools will be most interested in without getting into the specifics of your roles, but in general they want to see what you've accomplished in your professional experience more than what your required functions were. What kind of leadership have you been exposed to? What sort of teammate are you when working together? Your business skills and profile are critical, so be as specific as possible in your resume and essays. You say you've trained other people - this is a good example of being a leader in a business setting.
Expand on the rest of your experience. Have your extracurriculars involved anything that would be business related? You will also need to highlight your future goals, both long and short.
We'd be happy to discus your profile further. Please contact Meli at Meli@mbahouse.com
and we can continue the conversation!