as others are saying, find out what matters and focus on that. For any specialty:
1) good step scores
2) good clinical rotation grades / recommendations
for more competitive specialties, find out which of these apply:
3) aoa
4) research experience
5) away rotations
6) leadership or other extracurriculars (i don't think this is super important, don't spend a lot of time on this if you don't want to)
i think it is pretty much that simple. Focus on where the highest returns are for what you want to go into. Generally that means doing well with whatever is happening at the time. Knowing your ms i - ii basic sciences cold will help you when step 1 comes around, and will help prepare you for clinicals. Having a good attitude, knowledge base, work ethic, and bedside manner during clinical rotations will help you get good grades and good rec letters. Take each step seriously as it comes, give it your best, and you will probably end up somewhere good.