Scene management is a big one actually. Checking for safe conditions, no downed power lines, leaking gas tanks, precarious positions of vehicles, managing traffic around the scene, setting up road reflectors, checking for fire conditions.

If you aren't comfortable with performing first aid then one can always act as the "gopher" or communications relay for those with more experience. There is always something everyone can do at an accident scene, even hanging back in the car calling for the ambulance/fire/police and directing them to the scene.

While a kit is handy, emergency training is far more worthwhile. A little confidence and calmness from you will help calm those are involved in the accident and keep them from getting weirded out.