There are 18 Maha-Puranas total in which Matsya Purana is the oldest Purana and Brahma Purana is the first Purana of Sanatan dharma. The Padma Purana,

There are 18 Maha-Puranas total in which Matsya Purana is the oldest Purana and Brahma Purana is the first Purana of Sanatan dharma. The Padma Purana,