Like cmailliard said. ABC's.
As a first responder, your main job is to get advanced medical care for your patient.
That means get the EMT & Paramedics to you.
It is probably good not to move them because if possible spinal injury, unless your trained to do it, or EMS needs your help with the patient.
Do your best, try to get vitals if possible while waiting for EMS. (pulse/respirations/mental state)

Cheers, you did good. Most people would just keep driving.