Pretend your confident.
In class, say hi to the person next to you. Start with something basic like :Nice shirt where did you get it? OR So how are you liking this class?... something easy. Let the conversation flow naturally.
Act confident, people won't know the difference.
Confidence is being able to say Hi without pooping your pants. Confidence is NOT being snobby. Sometimes people get that mixed up.
Be positive, even fake it, soon enough it'll come to you. If you think positive, things will come out positive-- I can guarantee it
sARAH