Understand what Arabic FusHa is
Classical Arabic, also known as Quranic Arabic, is the form of the Arabic language used in the literary texts during the 7th to 9th centuries, from Umayyad and Abbasid times. Classical Arabic is based on the medieval dialects of Arab tribes. Modern Standard Arabic is the direct descendant used today throughout the Arab world in writing and in formal speaking, for example, in the news, books and literature, newspapers, magazines, official documents, in formal speeches, and non-entertainment content. While the lexis and stylistics of Modern Standard Arabic are different from Classical Arabic, the morphology and syntax have remained basically unchanged.
Arabic is one of the six official languages of the United Nations
Modern Standard Arabic is the literary standard across the Middle East, North Africa, Horn of Africa, and is one of the six official languages of the United Nations. It’s the official language of all Arab League countries and is the only form of Arabic taught in schools at all stages. In the Arab world, little distinction is made between Classical Arabic and Modern Standard Arabic, and both are normally called Al-FusHa in Arabic, meaning “the most eloquent Arabic language.”
If you are interested in learning Arabic FusHa, which covers both the Modern Standard Arabic and the Classical Arabic, then you can learn it at universities or language schools. But if your goal is to interact with native-speaking Arabic people, then you need to learn to speak in an Arabic dialect.