I've always been a very shy person, especially with public speaking! But I've gotten much better over the year's so that even though I FEEL nervous it doesn't show that I am nervous and people think I am confident :D You can practice speaking in front of a mirror, or even recording yourself on your cellphone to listen to when you're finished. Try to do it without writing down what you want to say first, just pick a subject and start speaking about it. Keep going as long as you can even if you mess up or fumble your words. The idea is to help get rid of the fear of messing up in front of an audience. The more you do it the less afraid you will be. If you live with family or friend's you can practice in front of them as well. Just start talking about a subject you like (science, art, a video game or movie you really like) as if you where giving a speech to a big audience. One way I get ready for public speaking is to pretend I am a more confident version of myself. Imagine a character you look up to, someone who isn't afraid of anything and you pretend that while you're speaking your that person. You become more confident just by imagining yourself as being that way. The more you tell yourself that you're strong and not afraid the more you actually become that way.

Just imagine that the audience is almost all of your friends and you are sitting at the fire and telling very interesting story. Do not consider the audience as judges :) Life is so simple and cool

and this is something I can't ever do it!

Someone told me that i can do that by seeing in the middle space between the eyes of the audience ,the called it the third eye theory

I'll search for it :) however I tried many things and one of them worked