Complex sentence: His earliest training was in his native town of Belluno with Antonio Lazzarini, then moved to Venice, to the studio of Gregorio Lazzarini and later that of Sebastiano Ricci.
Split into simpler sentences: His earliest training was in his native town of Belluno with Antonio Lazzarini. He then moved to Venice, to the studio of Gregorio Lazzarini and later that of Sebastiano Ricci.