Basically, another, "Do I have a chance of getting into Brown?", question.?

You can take the premed classes at any 4-year college or university; you don't start studying to be a neurosurgeon until after your surgical residency, which is 13 years after you start college. Not in college. Brown has a weird grading scheme and requirements, so that actually probably isn't the best place to do premed. You'll have a good shot at good schools, but you need a lot more than great grades and a few activities to get into a top school.