How did Napoleon’s conquests change the rest of Europe?

Napoleon's popularity as a military hero made it fairly easy for him to claim power in France in 1799. On declaring himself emperor, he immediately began to spread his influence, leading conquests throughout Europe. Between 1799 and 1806, he managed to defeat European armies in Austria, Russia, and Prussia on multiple occasions. His campaigns led to the dissolution of the Holy Roman Empire. He also formed a practical alliance with the Catholic Church.
Napoleon’s domestic policies also had a significant impact on Europe. In 1804, Napoleon established the Napoleonic Code, a unified collection of civil laws based entirely on secular reason. The Napoleonic Code had repercussions throughout Europe, laying the foundations for the development of other nations' legal codes. The code was implemented in all nations under France’s control during Napoleon’s reign, and even today, it is the foundation of civil law in Belgium, Luxembourg, and Monaco. (Britannica)
Napoleon's influence on Europe wasn't just geographical or political; it was also ideological. In each territory he conquered, Napoleon spread the progressive ideals of the French Revolution. He promulgated the idea that Europeans were trapped under the tyranny of an old system and presented himself as the hero who would free them from it. The spread of these ideas created a strong nationalistic sentiment throughout Europe and the Americas that would help lay the foundation for the numerous revolutions of the nineteenth century.
Only Britain managed to resist Napoleon's spreading power, and in response, in 1806 Napoleon created the Continental System, blockading any nation under French power from trading with Britain. Unfortunately for Napoleon, the Continental System wasn't a particularly effective punishment for Britain. While it decreased British exports to continental Europe, Britain's trade with the rest of the world expanded. On the other hand, Britain's hard line against the blockade—stating that they would sink any ship in British territory that obeyed the Continental System—led to massive conflict with American trading ships, eventually helping prompt the War of 1812.
While Britain remained economically stable, France and continental Europe suffered from the blockade, as they relied on British exports for manufacturing. Port cities like Marseilles suffered financially, and the price of food skyrocketed. By the time Russia withdrew from the Continental System in 1812, ending the blockade, Napoleon's power had weakened significantly, and in 1813, he was exiled to Elba.
Ultimately, Napoleon's conquests lay the groundwork for the first-ever European continental alliance. The success of the Napoleonic Code influenced the systems of law in other European nations, the spread of nationalism inspired numerous political movements, and the failed Continental System offered clues about how European states could collaborate together in the future. The Congress of Vienna in 1814 was the most significant result of Napoleon’s conquests, as European nations met to discuss ways to avoid the rise of another Napoleon-like figure. In these meetings, the Congress created new goals for a unified Europe: encouraging peace and comprise instead of war, abolishing the slave trade and enforcing religious toleration, and creating a workable example of an international alliance.