For a junior scientist one of the most important occasions for speaking is the 10-minute presentation, and this will be the focus of this talk. Indeed, if you can plan a 10-minute talk, then a longer one, that might be delivered at a seminar for example, is well within your grasp. There are four things to remember when delivering a paper. If you normally have a light or high-pitched voice, work to overcome it. Do not make the audience have to work to hear you.
Shyness is never an acceptable excuse for a poor performance.
You are a professional. Set aside all worries about shyness for the moment. Never apologize for your work no matter how nervous you are. You should speak at a rate of about 100 words per minute, so in 10 minutes that is about 1000 words. Once you have reached this stage, do not be misled into thinking you are finished because you are NOT going to read this paper at the meeting.