There are many "kinds of expiration". A very expired film can be perfect if it was aged sealed and frozen, or refrigerated, while less aged film can be damaged because of several storage conditions, temperature ? underground ? (protected aganist Muons/Cosmic rays ?)
With that 10 years old film I'd shot first roll with bracketing mode (0 , +1 perhaps) if rating nominal ISO 320. Also in the first roll I'd shot some reference scenes with a wider bracketing, to learn both effective speed and how film works in different conditions.
Having 50m first you should do is testing well this film to see how it works and how can be used to suit your taste. If film is damaged it will have some fog, some speed loss and color shifts, so it would be perfect for lomography !
...but probably you have a jewel, Eterna is pure beauty for some, still it can suit your taste or not. You will find a bit of grain in the 500, for motion pictures this is not bad because we don't see the grain at 24 frames/s, instead grain makes amazing swirls on motion and it becomes hypnotic, immersing the viewer inside the movie.
Personally I felt that the 500 coarseness (in the shadows) can team with defocus, for portraying people volumes can be worked by taking advantage of glare and powerful texturized highlights on skin. I've experimented more with Kodak Vision 3 and only two rolls with Eterna, I found both have the same soul but diferent bodies. Vision is more direct and spectacular, Eterna is oriental refinement and sophistication.