1. Nervousness is natural and normal. There is nothing wrong with you, Don't panic.
Initially everyone feels some physical reactions like pounding hearts and trembling hands.
Don't associate this with the sense of performing poorly.
The best way to overcome anxiety is to prepare, prepare, and prepare some more.
Go through the content several times. Once you achieve your comfort level, perform against the mirror.
2. Know your audience. Your speech is about them, not you.
This will help you decide choice of words and level of context.
3. Organize your content in the most effective manner to attain your purpose.
Create the framework for your speech. Write down the topic, general purpose, specific purpose, central idea, and main points. Make sure to grab the audience’s attention in the first 30 seconds.