When you are giving a presentation or speech, your body language and how you hold yourself in front of a crowd speaks to them as much as your words do. And part of not begin nervous in front of people when you are doing public speaking is not "acting" nervous.
If you have complete control over your body, your face and your hands, you can perform relaxation in front of people and you will actually accept the idea that you are relaxed and begin to feel more at ease as you do your speech.
One problem that you often see in public speakers who is the use of the eyes. It's extremely easy as a public speaker to want to look at your outline or your written out speech throughout your presentation so you never get lost or have that terrifying feeling of not knowing what you are going to say next.
That is why many people who do not become skilled at talking in front of crowds write out their speeches word for word and just read it to the group.
The problem with that approach is you have been asked to give a speech, not a reading. And many adults take offense at being read to. An audience wants to hear "from" you, not just hear you read.
If that was the only value of a public presentation, you could just hand out your speech as a white paper and let them read it and not have to get in front of people at all. But that is not as effective as public speaking, particularly if the purpose of your speech is to convince or to sell.
So the question comes up of where to actually look as you give your speech. Many speakers look at a spot at the back of the room because looking at the faces makes them nervous. This is better than staring down at your papers the whole time.
For one thing, projection is a big part of getting your message out there. And even if you are using a microphone, if you speak "out" into the crowd rather than down, your voice will be clearer and you will naturally use your diaphragm to do well at enunciating each word.
The other value of looking at the back wall is that it will help you project your voice, particularly if you are not using amplification. The old actor's motto of "performing to the last row" applies here because it means you consider everyone in that hall to be your audience, not just the people on the first row. So there is some value to that approach.
However, one of the most valuable ways you can really connect with your audience and get your message across is to make eye contact with the audience. Eye contact is commonly used by sales people to create a bond with the customer and that bond helps close the sale.
But even if your presentation is not necessarily a sales situation, eye contact will get your message across. And that is what you got up there to do in the first place.
Eye contact makes the audience look at you. It keeps them attentive. To use eye contact to its maximum value, move your eyes from audience member to audience remember and speak to that individual directly. That eye contact will actually be felt by everyone around that individual and it rivets the listener to you.
Don't linger on one person because you don't want to stare but by becoming skilled at using eye contact as you speak to a crowd, you are taking control of the presentation to make it do what you want it to do. And having control is a big key to success in public speaking.