Soap box car!! I am in a boy scout group and need to build a soap box derby car from scratch... I need help!!?

I am in a boyscout group and I need to build a soap box derby car... From scratch!!! We are totally confused and have no idea what to do, and the leaders are going to beat us!! I need all the ideas I can, including how to break and how to turn... I NEED YOUR HELP!!!!