Is the prayer of one who has read about the personalities of friends through horoscopes accepted, and is this sin forgiven him given his ignorance of its prohibition?

One must completely refrain from reading horoscopes, as it is forbidden. If someone did so out of ignorance, there is no sin upon them. However, if they were sinful, sincere repentance erases what came before it. One must also adhere to obedience to Allah Almighty and believe that none knows the unseen but Him, and not return to reading the words of soothsayers and astrologers. If repentance is sincere, Allah will forgive His servant and accept their deeds and acts of worship.