In this dream, after walking down a long school hallway, saying hi to 3 of my old school friends, one of my nicer teachers set up a nice picnic outside even though only a few students came.
It's interesting that you dreamt about being back in school and seeing old friends. This may symbolize the past coming back into your life, or a feeling of nostalgia for a simpler time. The fact that the teacher set up a picnic, even though only a few students came, could represent a desire for connection and community in your waking life. It could be that you are seeking out these things, but perhaps you aren't finding them as easily as you would like. Alternatively, it could mean that you take comfort in the small things, and appreciate the effort that others make to create a positive environment. Overall, the dream suggests a longing for a sense of belonging and positivity, and may be a reflection of how you feel in your waking life.