The first thing you should do, obviously, is to seek medical treatment for your injuries. While paramedics might treat you at the scene, you also should go to the emergency room to ensure your injuries are not more serious than they appear.
Further, you should undergo an exam by your regular doctor as soon as possible following your accident. Not all injuries are immediately apparent, and you want to ensure that you can establish a connection between your accident and your injuries. The best way to do that is medical attention as soon as possible after your accident. If the paramedics say you’re fine except for maybe some road rash, go to the emergency room. If their doctors there see nothing obviously wrong, go to your doctor.
Neither paramedics nor ER doctors have the time to deal with someone who appears to okay. However, symptoms for many injuries do not manifest for days or even weeks, particularly with brain or soft-tissue injuries. Such injuries can have long-lasting consequences.