You can just say your name and that you don't like talking in public because you have a stutter. As much as you feel comfortable saying. Or even tell the lecturers your feelings and ask them to introduce you. Or ask anyone. Give them a note to read out. Good luck. Hope you enjoy it. PS I don't have a stutter but I'm terrified of speaking in front of people. And avoid it if I can. Uni does force you to do it though, so I'd take the opportunity to humiliate yourself in a place where many others will be doing the same thing, though you may never notice it. Good practice, glad I did it, but man I avoided it since.