You grow up really, really fast by the time you're done with high school and head off to college, I promise you that. College seems daunting at first, but after your first two weeks you'll be all "holy carp this is so much better than being stuck in school for 7-8 consecutive hours a day"
I wasn't at all popular in high school, lol! Luckily my school was huge in terms of the number of students, so I was able to find a friend group with similar interests that I still hang out with. Now, I didn't go out of my way to be purposefully unpopular (if that makes any sense), I just didn't need to be super popular since I already had my group of fellow supernerds to hang with.
That said, I did try to be very sociable with just about anybody and (after my sister finally convinced me to do this) I dressed in not-lame clothes such that I gave off a better first impression. That all payed off since I learned how to carry myself around people I was interested in, and after one really failed relationship (that I admittedly learned a lot from), I'm now marrying the the person I asked to prom in 2008
I should say that I'm super, suuuuuuper lucky to have found my significant other so early; it's somewhat unlikely to find someone who is that compatible before college, and so I am really fortunate in that regard
In general, it's probably easier to find someone after you graduate high school since there are usually much more people at a given college than a high school, and there are MANY more activities/groups/etc. where you can meet people with similar interests. Did I mention college is awesome, lol?