Tensing up because you have to speak before a group of people is quite normal, and it happens to everyone including the experienced ones. The difference is that they have learned to handle and manage it, actually transforming it into positive energy: enthusiasm. The good news is that everyone of us can do it!
Being able to cope with it doesn’t require any special skills neither is rocket science. What you need is experience, preparation and a positive approach.
You cannot buy the first one, it takes time but eventually it will come to you. If you avoid presenting you will never build your experience … so go for it.
Preparation is crucial and that’s something you can do from day one. Prepare your speech, your preparation, practice it many times it will help you burn off some nerves.
Finally a positive approach is again something you should do already. Don’t worry over things you cannot control (how are they going to react, am I going to start on time, ecc…) but rather on what you can manage: your preparation, what you know, your good intentions.
You can already smile, overcoming fear of public speaking is achievable with a little time, a little confidence and few tips (I am in for supplying those ones)!