When it comes to the political changes, the Tokugawa shogunate was introduced which centralized the government. Unlike before where there were many smaller sovereign areas, now there was a huge centralized feudal country with smaller vassals who all reported directly to the Tokugawa shogun. The country became more militaristic.
Economically, the country prospered at first. The Shoguns had numerous projects that they wanted and that cost a lot so they had Daimyos, which were like wealthy feudal lords, participate in these endeavors or they would be punished by the shogun. The country started developing rapidly because they started commanding the economy. It was only later during the Tokugawa shogunate that things started going badly because Japan became way underdeveloped compared to other nations of the world.
Socially, the classes were changed and the power between them was changed. The Samurai, otherwise known as Bushi, became much more important. The peasantry was completely disarmed in order to prevent things like rebellions and Samurai got a huge amount of power since they were the army of the nation and the nation was a military one.