Community service might work for some people by bringing a grander-than-self altruistic purpose/meaning to their life, but personally, I have a feeling you actually need more of a pure Ego boost.
If you really think your social 'position' is the cause of your inability to approach her, lets see: Bottom of the social ladder? So fucking what, who even decided on such a ladder? I seriously doubt your peers posted a ranked list of who's on top and who's at the bottom on the school's bulletin boards or some such, so this "bottom of the social ladder" thing is wholly based on YOUR whole perception of a "social ladder". If your peers ignore you, its because you aren't actually trying to show yourself to them, you are actively trying to hide yourself, most probably to, as mentioned above, avoid any possible rejections by your peers/crush. To avoid being hurt.
Well, lets go on to analyze why you'd be afraid of being 'hurt'. Even if you are rejected, mocked, and then ignored by peers, what would you have lost? This is high school. Would you lose a hard-earned reputation? Your ability to join a good college? Your chance to have a decent job and life in the future? "Street-rep"? What? There is nothing your peers can possibly do to inflict lasting harm on you. Or any actual, non-imagined harm. They have a problem with you? This dislike you? Fuck them, why the hell would YOU care about what such people think about you? And this also applies to your 'love': Ask her. Talk to her. If she rejects your best attempts, then she never was meant for you ANYWAYS. If she accepts them, good for you. The only way you can screw this up is doing NOTHING and thus perpetuating your self-deprecation, perpetuating the perception your peers have of you, AND being guaranteed of not getting the girl.
I honestly can not give you precise steps to follow to get the girl, but none on this forum can, simply because WE ARE NOT YOU. We do not know the exact situation, your exact likes and dislikes, and the girl's exact likes and dislikes (and if you truly 'love' her that much, YOU better now her likes and dislikes). What I can do is assure you that, once you develop some proper egoistical self-appreciation, it will all just "come with the flow". You'll be able to care properly about YOURSELF, and thus be able to set some proper goals for YOUR life, disregarding others. And I guarantee you, unless the girl is sadistic, she's far more likely to accept a confident and independent person that obviously knows what he is doing and where he is going, than some person fawning over her uncontrollably and seemingly existing solely to worship the dirt she walks on. Plus, that way you'd have, you know, somewhere to go to in life whether she ends up rejecting you or not. What's the point if she DOES accept you and then a few months later she graduates and you have absolutely nothing to look forward to in life? Do you really think you'd get to keep seeing her then, even from afar?
So pick up your act and FEEL GOOD ABOUT YOURSELF. You are you, you are awesome, fuck those who say otherwise.
Yes, I get very angry at self-loathing people, especially in the middle of the night.