Many people are terrified by the notion of having to do public speaking, the reason for this is they fear the sound of their own voice, whilst this is quite natural a few things can be done stop this fear.
The first thing not to do is to worry about the number of people you'll be speaking to, just focus on one person in the middle of the room, don't gaze at them but use them as your main focal point.
Secondly, make sure that you type out your notes for the speech, don't hand write them. The reason for this is so you can see them easily, make them clear and concise.
Please take some time to write your speech, make the words mean something and don't forget to make the speech memorable.