If part of my elbow is out of place, would i know? i fell on it and cannot fully straighten it.

Elbow: Give an acute injury time to resolve. RICE. Rest ice compression elevation. If pain bruising or restricted motion persist, get an xray

Possibly: If your motion is not the same after a fall as it was before, something is not quite right. It can be a subtle fracture such as a radial head fracture, you could have torn or stretched a ligament. Don't hesitate to be seen for it for an accurate diagnosis.