As for Black Friday, it's not something you participate in, it's a phenomenon. The day itself marks the beginning of the Christmas shopping season, as such, there are a lot of people who go do their Christmas shopping (duh). When this happens, many stores go from red ink (red signifies negative, meaning debt) to black on their financial reports, and since this day is always on a Friday (it's the day after Thanksgiving, which is always on a Thursday), it's called Black Friday.
There, you learned something new today.