The XVIIth century was a time of change for the nobility. Most of this century was under the rule of the Sun King who continued the work of his predecessors into centralizing his power.

The times of feudalism were mostly over, meaning that nobles no longer had the power they previously had . Many people ignore that nobility and royalty are two different " entities " which had trouble co existing.

During the " Middle Ages " or more precisely during feudal times, nobles and feudal lords had a lot of power that they often gained by swearing an oath of allegiance to a King ( for example ), in France it was called the hommage lige . By swearing fealty to a King, you gained lands and power but except honour, barely anything else prevented you from swearing an oath to a foreign King ( for example the Dukes of Brittany during the 100 years war who had swore an oath to both the Kings of France and England and thus becoming very powerful, sometimes more than the King ).

It lead to all kinds of troubles and sometimes civil struggles between a King and his vassals. It's one of the reason the Kings of France, and plenty of others, worked in order to gain more power for themselves and reduce those of their vassals. At some points, feudalism ended in France and it turned into a more absolute monarchy.

The reign of Louis XIV is the perfect example. The fasts of Versailles that we all know about did not exist by simple random facts, most of it was perfectly wanted by the monarch. By having the more powerful nobles at court such as in Versailles, most of them doing useless activities, were a way to keep an eye on them.

Most of the nobles at court belonged to the High Nobility, often very old families and very rich ones. They were the most troublesome for the monarchy as they often were greedy and did not shy on various plots and even revolts ( the Fronde ). After all, they tried to take profit of the death of Louis XIII and Louis XIV proclaimed that no man in his Kingdom would be more powerful than him. This was directed toward these plotting nobles.

So nobles had less power than before. Tournaments were forbidden since the death of Henri II, their lives were directed toward the royal court for many of them. A new kind of nobility emerged ( not only in the XVIIth but it was very much present at that time ) called the noblesse de robe. These were wealthy families but of " humble origins " that bought their titles and positions in the administration ( judges, magistrates,...Etc ). They were despised by the noblesse d'arme who were very old families who made their names through the military.

So your life would depend on plenty of things : whose son you were, where were you born and how many siblings you would have had.

If you were the son of a noble living at court, you would presented to the high society very soon.

Were you wealthy ? ( indeed some noble families were poorer than land owners )

Were you born in a province ?

If you were the first born son, you most likely would inherit your father's or mother's lands and titles. A second son would generally try a military career ( the military was getting more and more professionalised, though high ranking officers often bought their positions but some men made their names with their skills and not wealth ). A third son would join the CHurch. But no obligations in that.

If you were at court, you would most likely hate the King and he would be very suspicious of you because he took most " ancient " powers from you and you may be plotting against him. In fact, Louis XIV may have had more loyal valets and footmen than loyal dukes.

Keep in mind that many nobles would follow the King and he wants you to do just that ( at his annoyance maybe but it was the game ). That is a reason why the King's day was so ridiculously timed and scheduled. You would want to buy your place at King's rising or sleeping ceremony so that you would be closer to him and maybe earn his favour. In exchange he would keep en eye on you.

To be honest, it was unbearable for the monarch but Louis XIV took it very seriously, it was his duty. Later in the XVIIIth century, Louis XV and Louis XVI showed how awful this was and ran away as much as they could from the " etiquette " and sought privacy. It ended to be vital in the weakening of the monarchy before the revolution.

The XVIIth century, at least under Louis XIX was less troubles century in terms of civil turmoils. The wars of religion were over ( it actually lead to the suspicions Henri IV, Louis XIII and Louis XIV had on the nobility, too keen on plotting and revolting ) but many foreign wars ( such as the 30 years war ) happened in which nobles took part as officers. Some made their names, some died and some only played the general.

Also, it was the Grand Siècle with the Scientific Revolution. Many nobles made a name for themselves in their researches in various scientific fields.

This website is interesting, at least for Louis XIV.

If you want a read, maybe not easy but a reference you could have a try at the Memoires of Saint-Simon, relating his life at the court amongst other things.

Maybe you can even find for free somewhere on the Internet or at least parts of it ( because it is a huge read divided in several books ).