Anyone badly injured in a motorcycle accident may not have the ability to do much at the scene of the crash. If possible, take photos and videos of the scene, your wrecked bike, and the vehicle that hit you. Get the name and the insurance of the driver. If there are eyewitnesses, collect their contact information.
If you are up and walking around, you may not think you were seriously injured. However, always seek medical attention. Once the adrenaline rush from the impact wears off, the pain may start. Many injuries do not show up immediately.
Going to the emergency room or otherwise seeing a doctor is not only wise for your health, but the lack of a prompt medical examination means the insurance company will either minimize the injuries or allege they did not occur due to the accident.