At least in America, and possibly/probably in the UK, schools do not teach the French Revolution in a very complex way. It's highly simplified and used more as a narrative about our own self-definition: both in a kind of nationalistic way (THEY had louche, decadent, cruel aristocrats, WE have rich people who are somehow more connected to the common man and a government with controls in it to protect against tyranny) and in a deterministic one (if the peasantry is beaten down with terrible treatment it will rebel violently); in America, it acts as a parallel that helps to reinforce the idea that the American Revolution was a necessary response to British governance, and a foregone conclusion.

What I'm saying is that it's a lot more complicated than the French monarchy being uniquely awful to everyone but the clergy and nobility, and the poor finally going, "we've had it, let's chuck you out and create a new form of government on our own," to the strains of We're Not Gonna Take It. There were a number of factors that developed through the eighteenth century, and led to turning point after turning point that eventually caused a civil war. Historians have been able to go from the initial justifications to the Marxist class-struggle explanation (strong capitalist bourgeoisie beats dying aristocracy dependent on peasant exploitation) to a revision that makes everything about factional political responses to another revision all about ideology because of this complexity to a synthesis of many different social, economic, and political factors. Newer scholarship also doesn't divide people into rigid classes labeled "noble", "peasant", or "bourgeois", but looks at the many different social groups that interacted with each other: the old nobility, the legal community, peasants with little land, prosperous farmers, artisans, merchants, etc.

But as far as issues that specifically affected the poor go, I would start with the fact that there wasn't much food. The population increased throughout the century due to a rising birth rate and falling infant mortality, while food production kept juuust in front of demand; every so often there was a bad crop that devastated the rural poor who were dependent on agriculture, and also badly affected the urban poor who needed to buy food at low prices. Wheat prices rose throughout the century, spiking during crises (such as during the 1770s, and in the year preceding the Revolution, not coincidentally) but never quite coming back down to where they started afterward, and periodically there were demonstrations in cities against the high prices bakers were charging for bread during times of flour scarcity. Population increases also put more pressure on poorer people with more children (more dowries, the inheritance is split up more, etc.), and rents increased. At the same time, those involved in manufacturing and international trade did very well, bringing up the standard of living that many aspired to and increasing the distance between them and those below.

As far as the actual government policies went, though, things were less straightforward. So, the French treasury was never very robust, because France kept getting involved in expensive wars. By the late 1780s, it had just fought the Seven Years' War in multiple theaters (in Europe as well as in America - what we call the French & Indian War) and followed that up with its aid to the American War of Independence, which left the coffers empty but the administrators unwilling to declare bankruptcy and nullify all debts owed. The system of taxation wasn't efficient, with many members of the nobility and bourgeoisie being exempt from it, and the government often had to rely on huge loans with high interest rates, which is obviously not a good situation for building a budget surplus down the line; because the monarchy was technically not subject to human laws, a whole complicated system had to be devised to make French lenders feel secure that they would see the money they loaned again. Overall, taxes were more unwieldy and inefficient than crushing: because the nobles who were members of the parlements - not equivalent to Parliament, but regional bodies of judges that had to accept and publish laws, taxes, etc. for them to go into practice - refused to accept direct taxes on themselves, new methods of gathering an indirect tax here and a fee there had to be grafted onto each other, and typically had to hit commoners harder than nobles in order to happen. This actually began to be reformed about a decade before the Revolution by Louis XVI's director-general of finances, Jacques Necker: he essentially took a machete to the shambling structure and built a new, centralized system that benefited the treasury ... but not the rich middlemen who'd previously earned salaries and skimmed revenues, and those who followed him kept borrowing huge sums to keep the whole thing afloat. Just before the Revolution, there was another flurry of reform that again caused major unrest, and the crown was still unable to pay loans back or make payroll.

There are a lot of things to say about philosophy in the lead-up to the Revolution, but these were not really of interest to the poor. However, once we get past people's immediate problems with food, taxes, and lodging, there is a more cerebral issue: their views of Louis XVI and Marie Antoinette. As in any society, the day-to-day actions of the richest people were generally not well-known by the poorest - they tended to get their information from rumor and subversive, borderline pornographic pamphlets based on information passed to writers/printers by disgruntled courtiers who were out of favor, or just wholly invented. The queen was depicted as an insatiable and bisexual harlot, taking lovers in the marital bed while the king slept beside her or watched; I've written a lot about Marie Antoinette, so I'm just going to link to my profile section on the subject. Suffice to say, it was the equivalent of the National Enquirer telling you that the First Lady is having an affair and spending $15 million on secret getaways with her lover while a body double takes her place in the public eye. It was widely believed that she was a dangerous sexual monster, though, and while we tend to think now that all of the opposition to her was about disapproval of the wasteful and indolent rich, quite a lot of it was moral indignation over completely imagined events.

So what did the French poor want from Louis in the late 1780s? Largely for him to stop raising taxes that affected them, for him to reinstate price controls on wheat and bread, and for him to stop his wife from demeaning her position or else to divorce her and marry a princess from a country they didn't have a long-standing hatred of.