What kind of wrist exercises can I do with a scaphoid fractures?

Very little. I would recommend very little wrist exercise other than minimal range of motion exercises until you have confirmed that the scaphoid has healed. Timing of exercises also depends on the type of treatment you received.
Did you have surgery. I cast for a month after surgery and allow exercise as tolerated in cast. If no surgery, and depending on where the fx is on the scaphoid, i cast them in a long arm cast for 6 weeks with no exercise allowed then a short arm cast for 6 weeks with light exercise.