First and foremost, you should move to a safe location immediately to prevent any further injury or property damage.
Once you have properly evaluated your injuries and called emergency services (as needed), you should obtain insurance information from the other driver, including the details of their vehicle. Lastly, if possible, take photos of the accident, including both vehicles, and all injuries you suffered. To better understand your next steps, check out this video from our very own, Pete Leehey.
If you have follow-up questions, send 'em our way.