I guarantee that others in the class are equally confused and will be grateful to you for having the nerve to speak up. It won't take you too long to figure out which type you're dealing with. If you get one of the small minority of professors who are unresponsive or hostile to questions, don't push it. Go on to alternative sources. Even with the cooperative ones, don't spend too much time in class asking questions.
Some lecturers get irritable if they have to deviate too much from their lesson plan.
Ask them during their office hours instead. If something puzzles you and several classmates, try going as a group to the instructor. Even instructors who genuinely want to help, and welcome questions, will get testy if they think you are trying to get them to do your homework for you. Make it a rule never to ask your instructor for help on a problem until you have made a serious effort to solve it by yourself. When you ask, be prepared to show in detail what you tried and how far you got.