It creates a phobia, don't worry once started, fear ease. Do not over-prepare. Just have key words or notes which will assist you in keeping on track. Subject familiar or are you speaking over their level of understanding. Use buzzwords were possible.
Nobody wants to be the first to ask a question.
It maybe necessary to plant a person in the audience to ask the first one. Response should be in a welcoming manner. No condescending remarks. Your point may not be clear, show you are approachable with eye contact, friendly face and nod. In more formal presentations, such as selling goods, knowledge or services.