As a junior, you have much more time than, say, a senior, in August. But realize, we have no idea how you’ll eventually apply, what assets (more than which major or stats.) And we only know what you’ve told us. Eg, have you taken AP physics? You show a S2 score, don’t mention the class. It’s important for CS.
If you present as a CS
hopeful, with possible med interests (not uncommon,) a top UG college can look at your choices/thinking, experiences, stretch, patient contact, all that @Mwfan1921 mentions. Plus personal traits. (Even if you dont mention premed, they look for this range of different engagements, not just in your major.)
It’s not just about what college ECs the med schools want to see. First you need the undergrad admit. They expect evidence of their own.
And please think about rounding. This is holistic. Not just stem studies.