chocolate person. that was some bad advice.
Heres what you really have to do:
talk to her more during class and hopefully you can take the chatter out during lunch time and talk more personal things instead of just homework.
tease her, and argue with her in a joking way. be sure to laugh and smile to show her you're not actually disagreeing with her.
compliment her occasionally. Not too much though and make it subtle. LIke "you did really well in basketball!" or "you did really well on your science test!"
Don't follow her, or stalk her. This may scare her, girls don't like guys who are behind them 24/7.
Try to be interested in what she likes. LIke basketball for instance.
This may sound weird but girls actually like clever guys. Not ones who fake being dumb.
After getting to know her quite well, start talking more deep and personal. Tell her things about you that not many people know. Start being a little more serious. But you must trust her before telling her.
Congrajulate her whenever she does something good.
Roll up your sleeves with you wear school uniform. YOu don't want to seem closed off.
Break the touch barrier and put your arm around her. hold her hand to drag her somewhere. Hug her if its nessacary. If girls push you away sometimes its because they want you to pull them closer...
She may play hard to get so don't be confused if she doesn't show signs she likes you back.
She also may be shy so its best if you make the first move.
