Complex sentence: De Roore left with van Schoor for Brussels in May 1703 to find another teacher but was unsuccessful and then studied a while with the Guild of Saint Luke in Antwerp.
Split into simpler sentences: De Roore left with van Schoor for Brussels in May 1703 to find another teacher but was unsuccessful. He returned to his hometown where he studied for a while with the Guild of Saint Luke in Antwerp.