Born July 10, 1509 in Noyon, France, Jean Calvin was raised in a staunch Roman Catholic family. The local bishop employed Calvin's father as an administrator in the town's cathedral. The father, in turn, wanted John to become a priest. Because of close ties with the bishop and his noble family, John's playmates and classmates in Noyon (and later in Paris) were aristocratic and culturally influential in his early life.
Like many (most) of the early Reformers, Calvin was born in the Roman Catholic church. Like Luther, Calvin has a disagreement with his father over how his life would be spent.
By 1528 Calvin moved to Orleans to study civil law. The following years found Calvin studying in various places and under various scholars, as he received a humanist education. By 1532 Calvin finished his law studies and also published his first book, a commentary on De Clementia by the Roman philosopher, Seneca. The following year Calvin fled Paris because of contacts with individuals who through lectures and writings opposed the Roman Catholic Church. It is thought that in 1533 Calvin experienced the sudden and unexpected conversion that he writes about in his foreword to his commentary on the Psalms.
I recall that in the time of Calvin, "humanist" didn't carry the negative meaning that it does now.
Renaissance Humanism was a European intellectual movement beginning in Florence in the last decades of the 14th century. The humanist movement developed from the rediscovery by European scholars of many Latin and Greek texts. Initially, a humanist was simply a teacher of Latin literature. By the mid-15th century humanism described a curriculum — the studia humanitatis — comprising grammar, rhetoric, moral philosophy, poetry and history as studied via classical authors. The early beliefs of humanism were that, although humanists knew that God created the universe, it was humans that developed and industrialised it.
By 1536 Calvin had disengaged himself from the Roman Catholic Church and made plans to permanently leave France and go to Strasbourg. However, war had broken out between Francis I and Charles V, so Calvin decided to make a one-night detour to Geneva.
But Calvin's fame in Geneva preceded him. Farel, a local reformer, invited him to stay in Geneva and threatened him with God's anger if he did not. Thus began a long, difficult, yet ultimately fruitful relationship with that city.
It was in Geneva that Calvin did the bulk of his writing, studying and teaching. He remained there until his death in 1564.