In your dream, the school aspect represents a lesson to be learned, or learning itself. Clothes symbolize how people percieve you, or the image that you show them. This part of the dream shows that you are learning to or preparing to show something of yourself to others. A wedding represents making a commitment between some thought and action. So, a wedding dress indicates that you are wanting to show commitment about something. The darkness in the classroom shows that you are ignoring something behind the scenes of your life. The message you recieved are the thoughts, feelings, evidence that you need to procede. If the message was in fact 'do', this would make sense with the commitment theme. However, you are easily distracted, as you were in the hallway. Look over your life and see what it is that you are making preparations for, either mentally or physically, that you never actually commit to. The signs are for you to move forward but you are letting something hold you back. The problem is that you never allow yourself to focus on why you don't just 'do' it. Hope this helps, God bless.