Complex sentence: His career started at FC Girondins de Bordeaux, where he signed his first professional contract in 1975: one year later (1976) he won the Coupe Gambardella (French Under-18 Cup).
Split into simpler sentences: His career started at FC Girondins de Bordeaux, where he signed his first professional contract in 1975. One year later (1976) he won the Coupe Gambardella (French Under-18 Cup).