Dude, you're 17? 
Well anyway continue lifting; the girls will come. Females
naturally gravitate towards muscles, and humour, and influence, and
confidence, and intelligence, for the specimens with finer taste.
I'm eighteen, and personally if you have experimented enough, you
would know what girls are attracted to and hence know how to
improve yourself from there. Try observing the guys who have
girlfriends, or who tend to attract a lot of girls. What do they
exhibit besides good looks?
I'm going to emphasize the importance of "influence" here. Social
influence. The more friends you have, or the more girls you know,
the greater your chances are. Girls are very often intrigued if you
have a lot of chicks around you; they would want to find out what's
all the fuss about. Of course, to generate such influence in the
first place, you need to have genuine substance, or be insanely
good at manipulating your image. You must be capable in something
to capture attention, and with attention comes admiration, which
translates ultimately to influence.
One tip I found extremely valuable is that don't treat girls too
nicely. If you kiss their ass all day and whine whenever they don't
comply with your wants, they know that they have you by the balls
already. Just like shopping at the pasar malam, don't ever show
your interest in the goods to get the best deal out of the bargain.
If she knows that you're highly into her, she can sell herself at a
higher price and that makes things difficult for you. Conversely,
if you don't appear that you need her that much, e.g. don't
immediately agree to go out with her if she asks, pretend to have
some plans and say that you will confirm with her, and e.g. if you
ask her out and she declines, don't pester her -- she's made up her
mind -- but say something like "no problem, I'll ask
Lastly, muscles are good accessories too. 
