>>2 Its like you're asking the OP to turn her personality 180 degrees. Too hard!
>>1 You don't have to transform into a social butterfly, finding two or three can be enough. You just want someone to talk to right?
Just walk around the school and spot if there are people with similar personality like you and be nice to each other(don't be overly nice till you get misused. Eg. don't help other do their HW! It's their own duty to do their own HW or you can give tips in subjects you are good in).
You don't have to do a lot of big things to attract others. It's the small little things that attracts people who will stay with you(these are people you need to cherish not those party guys).