Pope Francis is beginning his first day at the helm of the Catholic Church, attempting to set out his vision for his papacy amid a testing schedule. He will lead cardinals in his first Mass, begin appointing senior Vatican staff and may visit his predecessor, Benedict, Pope Emeritus. The first Latin American and Jesuit pope has received a flood of goodwill messages fromaround the world. But the Argentine also faces a series of tough challenges. The Church has been dogged by infighting and scandals over clerical sex abuse and alleged corruption. Thursday morning saw Pope Francis begin the day with a visit to a Rome basilica, Santa Maria Maggiore, for a private prayer