I'd generally suggest that you take a few easy trail rides to get your confidence back. But, even though you say that you are physically unscathed, a dislocated shoulder will rule that out. Get some good physical therapy, regain complete strength and try again in the spring. Start in the dirt with a light bike. An XR100 would be perfect. Slide it in turns, practice hard braking, get used to losing and regaining control. Then move on to a MSF course with a heavier bike. But move at your own pace. Tension will ruin your control and that is essential to safe street riding. Good luck.