Learn Spanish (Latin America): El profesor te puede orientar sobre cuándo empezar la especialidad. - The professor can guide you on when to start the specialty.

This is an indirect question! In Spanish, just like in English, when you have a question word (like cuándo) followed by an action where the subject is already clear or general, you use the infinitive. Cuándo empezar translates exactly to "when to start".

Since it's not a real question with question marks, why does cuándo have an accent mark?

Question words (interrogatives) like cuándo, dónde, qué, and cómo always keep their accent marks when they introduce indirect questions. Even though there are no question marks here, cuándo is still asking an implied question ("when should I start?"), rather than just connecting two ideas.

Could I attach te to the end of orientar instead of putting it before puede?

Yes, absolutely! When you have a conjugated verb followed by an infinitive (puede orientar), object pronouns like te can either go right before the conjugated verb (te puede orientar) or attach directly to the end of the infinitive (puede orientarte). Both are perfectly correct and mean the exact same thing.

Why do we use sobre here? Doesn't that usually mean "over"?