* ¿Qué tal la escuela? This is a general and polite way to ask, similar to "How's school?" It literally translates to "How's the school?" but is understood as asking about the school experience.
* ¿Cómo te va en la escuela? This translates to "How's it going at school?" and is a more informal option, suitable for friends or younger people.
* ¿Cómo va la escuela? This translates to "How's school going?" and is a bit more concise.
* ¿Cómo te va con los estudios? This translates to "How's it going with your studies?" and is a more formal option focusing on academic progress.
The best choice depends on your relationship with the person you're asking and the nuance you want to convey. For most situations, "¿Qué tal la escuela?" or "¿Cómo te va en la escuela?" are safe and appropriate.