When you're involved in a collision you should always exchange information with the other driver or if the other driver is hurt this information should be given to the police.
First thing you should do in a collision if able is to call 911 and report the collision so the police and if needed an ambulance can be on their way if someone is hurt.
The police will make a report and they'll have your insurance and other information on file for the other persons insurance company should they need it.
Always report a collision to the police and don't ever leave the scene of an automobile accident because you can be in serious trouble.