Dreams can be complex and often reflect our subconscious thoughts, emotions, and experiences. In your dream, several key elements stand out that can offer insights into its meaning.

1. Identity and Perspective: Dreaming that you are a different race or identity, like being a black kid, may indicate a desire to explore different perspectives or experiences. It could suggest that you are examining issues related to race, identity, or feeling out of place in some aspect of your life.
2. Conflict and Rejection: The interaction with your friend’s family, particularly being told you couldn't swim and being called derogatory names, may symbolize feelings of inadequacy or rejection. This could reflect real-life situations where you feel misunderstood or judged by others.
3. Destructive Actions: Setting the place on fire could signify an intense emotional response to feeling marginalized or bullied. It might represent a desire to express anger or frustration in a dramatic way. This act could also suggest a need to break free from a situation that feels stifling.
4. Running and Hiding: Being on the run indicates feelings of guilt, anxiety, or fear of consequences. It might reflect real-life worries about facing judgment or repercussions for your actions or feelings.
5. Seeking Help: Finally, going to your teacher for help suggests a need for guidance and support. It shows a willingness to confront your problems and seek advice from someone you trust.

Overall, your dream may be prompting you to reflect on your relationships, feelings of acceptance, and how you deal with conflict. Consider exploring these themes in your waking life and think about how you can address any underlying issues. Talking to someone you trust about these feelings could be beneficial.