Bahá'u'lláh didn’t attend any schools

The education and instruction which Bahá'u'lláh received was limited both in nature and extent, as He Himself states in the Tablet addressed to Nasir’d-Din Shah: "The learning current amongst men I studied not; their schools I entered not. Ask of the city wherein I dwelt, that thou mayest be well assured that I am not of them who speak falsely."

In those days, the scions of noble houses were taught such matters as befitted their station in life, such as riding, handling a gun, wielding a sword, calligraphy, acquaintance with the works of the great classical poets of the land, a good reading knowledge of the Holy Book, the Qur'an, and hardly ever anything more. They were given such instruction by tutors, specially engaged by the parents, who were also required to teach them good manners.

- Balyuzi  (‘Bahá'u'lláh, The King of Glory’)