Chieko – I think your dream is asking the question ‘Who am I’? Because you can be loud and yet with a teacher you can be quiet. But in fact you can be anything you decide to be – we are all so many people inside that we have a wonderful choice. Think of all the people you have dreamt about. They are all you and you create other people you do not know.
As I say in the http://dreamhawk.com/dream-encyclopedia/the-magical-dream-machine/
“In your dreams you create such a world and such experiences. But perhaps you have not taken time to consider the wonder of your creative process in dreams. Every night you create a new drama. You conjure out of your own being the people, the creatures, and the surroundings of your dream. Then you give life to what you create not only life but purpose and drama. You are a supreme dramatist, playwright, actor and actress. You are the great Creator in your dreams. Considering this, have you ever wondered why that enormous creativity does not flow into your waking life? You can see that some people have that creativity and are enriched by it personally and financially. Why not you?”
As for your questions, I wouldn’t say that every dream has a meaning, but I am certain that we can get information from any and every dream. As I wrote in Dream Dictionary - Although the process of dreams might not be a direct attempt to present MEANING, a dream may nevertheless have a great deal of INFORMATION in it. This becomes clearer if we remember that not many years ago it would have appeared highly superstitious or suspect to claim to be able to tell a person details of their health and parentage from a sample of their urine or blood. Today it is common practice. We accept that a growing amount of information can be gained from these unlikely sources. Blood doesn’t contain meaning, but we can gain information from it. In a similar way a sample of our dreams can also tell us an enormous amount. Sometimes this data is obvious, sometimes it needs processing to uncover, as with urine and blood.
The other questions are best answered at length, so please see http://dreamhawk.com/dream-encyclopedia/your-guru-the-dream-step-one/