Young people dream of the sweet bell on Christmas Eve, which indicates that they can successfully join a certain group or organization, so they are happy. If you hear the ordinary bell, it means that your anxiety about the future is washed away by the news of distant friends.
Dreaming of harmonious bells means that you are anxious about the future, but the news of distant friends makes you feel relieved.
Dreaming that the bell rings after class means that in real life, you won the game beautifully.