Hey, i feel you. I don’t think people especially professors will make fun of you. I study myself and i am also afraid of asking questions in class. Maybe just try to talk to students next to you and ask them. I known it is hard to talk to new people, but small talk with other students worked for me. Start with short sentences, like asking for there name or if they understand the current subject and can answer your question. At my university in Germany we have a lot of group projects, which is nice to meet new people in a more private environment. I find it easier to talk to people in small groups, also i stutter less.