I would recommend starting with some bodywork classes, like pilates matwork (great for abs) or yoga to get your muscles used to working and stretching again...I would also recommend doing a ballet barre or a stretch and strength class(modifying the exercises as needed) so that your rotators get used to engaging properly. There are so many muscles that we use as dancers that don't get used in everyday life. Start slow and steady - don't rush into anything or you will risk a re-injury and some seriously sore muscles!
To lose the extra pounds you will have to do some cardio work - some low-impact options are biking (excercise bike) and swimming (if your gym has a pool), or the rowing machine. Weight training also aids in fat loss, as it keeps you muscles in fat-burn mode for quite a while after you have stopped your workout. Hope that helps a bit!