Same thing that happened when the soviet union stopped providing food. When a government ends its monopoly on food it does not mean there is "no food". No monopoly on education does not mean "no schools". All it takes for these services to continue is demand and supply. While demand and supply are unstoppable, rapid economic changes can cause temporary shortages.

A gigantic list of monopolies simultaneously stopping services like you describe would be quite tumultuous providing the free market had no warning time to prepare.

Even if the free market had time to prepare to avoid widespread shortages, for every one of the services provided, the population has likely forgotten or never known the value of many things. Value assessment and return on investment decisions will require constant adjustment, "Am I being ripped off for this tomato?", "Is it worth taking the shitty pothole filled road to work to save on tolls?", "Would paying for armed guards reduce the looting in my store enough to be worth it?", "Is it worthwhile to continue testing this new drug, or should we risk going out of business by causing negligent deaths that ruin our reputation?"

A question for you. Is slavery right/wrong mostly because of its effects/consequences on society, or because of moral theory? What is the primary thing that decides morality for you? Would you let 5 people die, or would you murder an innocent to save them? Should people use principals, or should they imagine what their own idea of good is, and do whatever it takes to cause that good?