I used to shoot a lot of Classical Ballet. It is very challenging. Let me see if I can remember any tips.
I used to use Tri-X at 1600 developed in Diafine.
Most important. Timing is everything. Remember that when something goes up, it is motionless for a split instant before going back down. Time your exposures for the peak of the action or the tiny momentary pauses in movement. This can be difficult and takes concentration but it will make the difference between a useless blur and a tack sharp shot even with slow shutter speeds. This often defines the skill of a performance photographer.
Practice holding the camera rock steady and releasing the shutter smoothly without moving the camera. Even if your subject is still, a tiny amount of camera movement can ruin the shot, especially when using telephotos at slow speeds.
While it is natural for a photographer to concentrate on faces and expression, the Ballet is all about the full figure especially the feet. Don't cut them off. Concentrate on the whole frame.
Lighting during the performance is constantly changing. There is a guy at a light board whose only job is to foil any attempts at successful photography. (not really, but it sure seems like it )
Beware the wing lights. As dancers approach the sides of the stage they can get blasted by those d@mned things.
While the overall stage may meter fairly dark The priciples, being followed by a spotlight can be very brightly lit. You can often run into more problems with blocked-up overexposure than too thin.
Try to be invisible. Stay out of the way of the dancers. More than once, while concentrating too intently on the viewfinder, I've nearly been stampeded by a flock of fairies. If you are shooting from the wings, shoot with both eyes open.
Shoot plenty of film. Some shots will inevitably be blurred or otherwise unusable. Nobody gets 100% under those difficult conditions. The successes are very satisfying though.
Best of luck and have fun!