Right now, your GPA looks fine. A 3.75 cumulative GPA is definitely in the competitive range for a lot of medical schools, but you'll want to order the most recent edition of the MSAR to see, specifically, which schools those are.
You're a little vague as to what your EC's are and given that they are just as crucial to your application as your GPA and MCAT, a more detailed description would be useful. It looks like you have research, that's excellent. You also mention volunteering experiences, but do you have both clinical and nonclinical volunteer work? You'll need both on your application, and 100 hours or more of each, minimum. You say you have leader skills, but can you prove that this is the case via one or two leadership positions in an organization or club on or off campus? You don't mention any shadowing. You'll want ~50 hours of that. I mean, adcomms want proof that you've thoroughly investigated the medical profession and know that you want to be a doctor. How can you know that if you've never shadowed a physician? What about TAing or tutoring? Most applicants have that. And what about a unique hobby that makes you stand out as a unique individual, rather than a pre-med bot?
As for the MCAT, a 30 should be your target. If you hit that, you're about at the average score of most matriculants. However, do NOT take the MCAT until you are ready. I pushed back my MCAT by a year and will now be applying in my senior year. Why? Because I didn't want to take a heavy science course load while studying for the MCAT OR go into the MCAT without having taken all the pre-reqs necessary for doing well on said exam. There is no reason to apply junior year if you aren't ready EC or MCAT wise.