Option 1: Asking for confirmation
* Are you going to have a nice class? This implies that the speaker believes the listener is going to have a nice class, and is simply seeking confirmation.
Option 2: Expressing concern/curiosity
* Will you have a nice class? This implies the speaker is concerned or curious about the listener's experience and wants to know if they'll enjoy it.
Option 3: Asking for feedback (less common)
* Did you have a nice class? This focuses on a past event and seeks feedback on the experience.
The best choice will depend on the context of the conversation and the intended meaning.