Well, they might have an interesting exchange about the Jedi Order. Ahsoka has seen the fall of the old Jedi Order, and Luke is trying to rebuild it. She could tell him about the mistakes of the past, like how the Jedi became too involved in politics and lost their way. And Luke could show her his new vision for the Jedi, perhaps more in tune with the living Force rather than just the strict dogma of the old order.
In fanfiction, if Ahsoka meets Luke Skywalker, they could potentially train together. Luke, having been trained by Yoda and Obi - Wan, could share his knowledge of the Force with Ahsoka. Ahsoka, with her years of experience in combat and her own understanding of the Force, could offer Luke new perspectives. They might go on adventures together, facing new threats to the galaxy.
If Ahsoka meets Luke in fanfiction, it could also be a moment of great discovery. They might find out about some long - lost Jedi secrets together. Maybe they stumble upon an ancient Jedi temple that holds the key to a new form of Force - using that neither of them has seen before. Their combined skills and determination could lead them to unlock these secrets and use them to bring more peace and stability to the galaxy.