well, you got into a bad car accident you said and I don't know to what extent but if your bones are fucked up you should probably just let them heal.
if there was one single exercise I can only recommend, i'd say squats. and do them right. not the half assed cheating powerlifting squats.
squat everyday or every other day. mix that in with pushups, pullups, light jogging and sprinting and you'd get fuckin jacked in no time. if you can, do deadlifts too.
the main difference between a casual athlete and a very good athlete, is by looking at how developed their poster chain (back muscles of the body) and legs are. those with developed posterior chains and strong thick legs (due to consistent weekly squatting), are stronger, have more power, and are faster giving them a huge edge.
