First of all, you are a sophomore. You have plenty of time to figure this out.
It also sounds like you are doing very well. Keep up with your class work, and keep doing the ECs that make sense for you. This will work out.
There are a LOT of universities that are very good for premed students, and that can set you up to do well on the MCAT and medical school admissions. Getting accepted to a university that is good for premed is the easy part. Doing well in the tough premed classes, getting appropriate medical-related experience, getting strong references, getting into medical school, completing medical school, …, there are lots of hard parts.
Medical school is expensive. Paying for the whole thing is one of the hard parts. However, this often means that a student might want to attend an in-state public school where admissions is easy and merit aid is possible, which might make the initial university admissions less stressful.
I think that I just figured out that you are in-state in Massachusetts. U.Mass Amherst is very good overall and very good for premed students. Some of the other out of state public schools on your list are likely to be pricier, with no significant advantage. BU and WUSTL are private. You might want to have your parents run the NPC for them at some point and see whether they are likely to be affordable. If you can it is a good idea to find an affordable university for your bachelor’s degree and leave some college $$$ in the bank or 529 fund to help offset the price of medical school.
If you are interested in medical research a PhD is another alternative to an MD. However, PhD’s and MDs do not do quite the same things, even when they are both involved in medical research. Which to go for is something that you do not need to worry about for perhaps 6 years, and many students get a bachelor’s degree and then get some work experience and then figure this out (so you might have even more than 6 years to figure this out).
For now I think that you are doing very well, and you just need to keep doing what you are doing, keep your grades up, get enough sleep, and have some fun from time to time.