Need doctor's help! what do they do in the er for big toe fractures?

Depends: On a number of things: is the fracture intraarticular, comminuted? Is the nail bed lacerated? Is there a hematoma under the nail plate? All these must be considered and taken into account. Tetanus shot might be required depending on the answer as may antibiotics. The toe/foot may be put into a cast, sometimes even surgery recommended.

Fracture: It has been my experience that they will generally diagnose the fracture , provide a surgical shoe and a referral to a podiatrist