Let's be honest here, are you lonely? If you are, you need to extend your bonds, and reach out for someone! A girlfriend/boyfriend will tremendously increase your confidence, and give you a reason to do better in life! Besides sex which is very good for your health, it's important to connect with them and ultimately, you understand yourself more even if the relationship ends quick.
So how do you get this soulmate (or not)? Well, first of all you need to stay /fit/! Remember the following quote made by Aristotle, longer version:
"Excellence is an art won by training and habituation. We do not act rightly because we have virtue or excellence, but we rather have those because we have acted rightly. We are what we repeatedly do. Excellence, then, is not an act but a habit."
If you can maintain something for around a week, trust me it WILL become a habit soon enough. If you are slightly overweight and physically unfit, do yourself a favor, put on some shorts and stretch, then run, and do not stop. This is how you can measure your will and bravery, your motivation versus your pain. Run every day, stretch then come back and feed on a cereal-bowl worth of veggies. These complex carbohydrates will keep you going for a very long time, snack on a few delicacies eg. chocolate, just know your limits and don't overindulge! If you aren't seeing any results, I suggest you aren't doing something right. See the 7chan /fit/ board, look for the main faq for more halp.:)
If you don't have straight teeth and are ashamed by it, visit an orthodontist and schedule some appointments for a great smile. Trust me, men and women of all ages from 14-40 get them, it's no biggie to be so old and have them on. 2 years of them, after a month you'll feel weird then after that it's nothing. DO IT!!!
Clear your face of acne, which means don't overindulge in sweets and wash it consistently. Brush your teeth twice a day, three times after eating some strong foods. You're not doing good in school? Either you aren't listening enough in class or you aren't doing the work given to you. Remember what Aristotle said, success is a habit! If you ever wanted to do ANYTHING (AND I MEAN ANYTHING), write it down, and break it down so that you can participate in it every few days.
Look in the mirror. How do you see yourself attractive? Women aren't hard beings to comprehend, if you can see other men as handsome (I hope there aren't any immature fucks laughing at that), you know women's tastes. Experiment with the way you look, I wouldn't recommend buying new clothing so fast if you aren't sure what you know suits you and what doesn't.
Listen to some new music, update your playlists regularly. Hear what other people do, read their thoughts and enjoy :) You like a genre, keep looking through it and find new music you enjoy... and it's easy to get into other genres you wouldn't imagine yourself listening to. Go outside regularly, if you really have no one to talk to, my suggestion is to get your basement-dwelling ass up and go outside, and see people! Talk to them, even strangers as long as they have a friendly attitude (if it's someone really uptight, I wouldn't suggest it.) People are very similar, they grow up different and sometimes believe different things, but there's a universal thought-process that everyone makes up: this is why awkward situations exist!
I wrote this extra long and somewhat exclusively for males, if you are female than sorry for the exclusion, I wouldn't know of much females that read my blog! But for everyone, be active and enjoy life, don't waste this precious time you have on ignorant trivial and wasteful tasks!
TLDR DO EVERYTHING YOU CAN TO BE THE BEST PERSON YOU CAN BE!!! :D