Hey, I was
exactly in your shoes when I was a freshman....
If you're really, really interested in these schools, here's my advice - print/download their applications - READ through them. See what they ask for - then pick an EC that you feel passionate about and DO SOMETHING WITH IT.
If you're into research - start thinking soon about projects like Intel Science and Engineering Fair, Siemens International, etc.
If it's medicine you're into - intern at a hospital/clinic/whatever you're interested in. Find out NOW. Don't wait. Many people, starting from sophomore year, begin to look through these activities - start earlier than them and look for some of these volunteering opportunities now/soon.
Starting your own business is also looked favorably upon - ONLY if you have a good/legitimate idea that can actually go somewhere.
Show leadership in something like soccer, if you're really into it - make varsity, be team captain, whatever.
Colleges don't like a "laundry list" of EC's - what they want is PASSION. They want to be able to read your essays/application and come away with someone that can make a difference on their campus. Honestly, Harvard gets so many applications from people with perfect GPA's and SAT's - do they take them all? Absolutely not! They choose people that are
interesting, people that can be a unique part of their campus.
If you're passionate about something,
show that you're passionate about it - the college applications/admissions process is not a time for modesty; it's a time for you to confidently (not arrogantly) portray WHO you are as an individual to the person reading your file.
ABOVE ALL:
Enjoy life. Really. I'm not joking around here. I hear so many of my friends (I'm a senior) reminiscing about freshman year...Do you really want to mess up one of the best years of High school worrying so frantically about college? Just do what you're passionate about - college admissions will come.
And, worst case scenario, you don't get in. So what? This year (class of '12) will seem like a cakewalk when compared to the class of '16 (that's your year) - there will be
even more people competing for almost the same number of spots. Just remember that if you're motivated and passionate, you can succeed
anywhere.
Good luck. See you back on these forums in a couple of years