A. First, get a police report. In most cases, when you call the police to the scene of an accident, the investigating officer will complete a report that includes information on all parties involved. Each person's name and address will be included along with the year, make model, VIN and insurance company with policy number.
To file a claim with the other company, you can either pass the report on to your Insurance company who will be happy to help you or locate the company claim information yourself, easily available on line, and contact them directly. The former option is preferred as you should let the professionals represent you to do it.