I want to start participating in class but I don't want to stutter and embarrass myself.

I want to start participating in class but I don't want to stutter and embarrass myself. I have never spoken out loud in class or anywhere else because I just don't like to sound and look weird with the faces I make when I try to get a sentence out. This is my last year of school and I want to talk as much as I want and whenever I want without having to account to anyone. The problem is that I barely spoke for 6 years, I forgot what it was like to communicate with people and I developed social anxiety because I didn't want anyone to hear me stutter.. I don't care anymore whether I have friends or not. I just want to talk whenever I feel like it. Advice?