I'm a shy person and I really need help to talk to this girl in my class.

Yes. Ask her a class-related question. It will make her feel smart and helpful. Set up a study date at her house, where she'll feel more safe.

Good luck!

Ask her to help you in the class, ask a question you might know the answer too but get her to help.

Well you have to step outside yourself in order to get somewhere new man.... just make small conversation start by commenting on something you heard her say or ask some question about class or make a comment on the class for example; if the teacher is a real pain say wow can you believe this guy? that will just start something small at least.....

You can do it just have confidence in yourself and really let it show...what ever you do though do not have one of your friends do it for you that is such a turn off! I hope it all goes well!

Ask her for help in the class. Then when she helps you just say "Oh you smell good today." or "You have pretty eyes."

Talking to girls is pretty easy.
Step one: Don't Panic
Step two: Don't put girls on a pedestal, they are regular people. Talk to them about regular people things. Start with "Hi", see how she is, then ask her a question designed to elicit more than a yes/no answer that will help you get to know her.
Step three: listen then respond.

Keep it short. Tell her that it was nice to talk and see her, and leave on a high note.