Im in the same boat as you.... just went to college less than a week ago as a freshman.
First of all, if its a severe problem of anxiety make sure your teacher knows. It might be hard to muster the courage up, but 1, who cares its just a teacher and he/she isnt gunna tell anyone what u told him/her, and 2, it will probably make things easier on you.
I found that with anxiety, simply letting people know yoru feeling nervous/anxious really helps relieve the feelings.
And if you tell the teachers and they see you acting funny they wont think anything of it.
Try and destract yourself too.... start doodling in your notebook, draw things that make you happy, even smiley faces if you want.