Once you've calmed your nerves, there are more steps you can take to advance your public speaking skills.
Engage in eye contact. Start in your day-to-day life by becoming "a real expert at one-one eye contact within a group," This is not just looking at a person's eyes but rather looking deeply through the eyes to the essence of the individual. This makes the connection that makes all the difference between speaking at or to an audience, and speaking with an audience.
Rinse and repeat. With speaking, like most things in life, the more you do something, the more work you put into it, the more you study and learn, the better you get.