Most of this is going to be very broad and ill-defined. Sources on the time period from 1911-1949 are pretty esoteric, and ignore the average Zhou. But despite this we have some pretty significant regional and international events from that time period that have come to define not just the modern history of China, but the entire world.

Fall of the Qing, rise of the Republic

In 1912 the Qing government formally abdicated after the signing of the Articles of Favorable Treatment. For almost all Chinese life was about to change significantly in many different ways. Starting with the elites, many landlords & other local elites found themselves with a substantial boost to their political standing. Once under the whim of the executive empire, the Republic of China's constitution and newly born parliament gave wealthy elites the ability to participate with more political agency. While most of us think of warlords automatically after the Qing, during the period of ~1912-1917 a strong bureaucracy made up of former Qing politicians ran many of the provinces south of Hebei. A well documented example of this is the governorship of Li Yuanhong in Hubei immediately following the 1911 revolution. Li himself was a leader in the Qing New Army and one of the higher ranking officers to order his units defection from the Qing. Li became appointed as governor of the province because of his martial expertise; Yuan Shikai was still marching south with Qing forces at this point. But in order to keep the local economy running and the troops paid and fed, Li was forced to cooperate with the local gentry who propped him up. So despite his position, Li was rather politically weak and would remain so even as he became president after Yuan.

After the death of Yuan (1916), things deteriorated quickly. The republic had always been weak from birth, but a series of political calamities, including an attempted restoration of the Qing in 1917, took China to the path towards warlordism, taking power away from politically independent gentry, and granting it to local military officers. For nationalists and revolutionaries (mainly students) life was uncertain. The lucky ones found themselves exiled (usually to Japan), the more unfortunate facing death sentences or assassination attempts. Many students again left China to join revolutionary cliques in Japan or in Chinatowns across South East Asia. They would continue their studies, learning from older revolutionaries like Sun, observing Westernization in Japan, or temporarily heading to the West itself to uncover its secrets of modernization.

Your average peasant was potentially subjected to all sorts of atrocities. When warlords brought conflict the usual wartime atrocities began: the raping, burned/destroyed goods, murder of civilians, forced migration, etc. China was a failed state, so unless you had money and the means to leave the nation or at least seek refuge somewhere safer (like Shanghai) you were stuck and subjected to the arbitrary whims of whatever local warlord was calling the shots that day. Taxes were high in order to support the constant state of war. And of course there was the looming fear of Japanese invasion. Japan invaded and conquered Qingdao in 1914, and began encroaching on Chinese borders soon after. In 1915 Japan had forced Yuan into agreeing to most of the original 21 Demands, which gave Japan huge economic monopolies across parts of Eastern China. People were losing their jobs, or being paid less under new management.

KMT rule

The 1920s saw the rise of the KMT and in 1926 they completed their military conquest of most of China, retaking Beijing and becoming the legitimately recognized government of China. This had the benefit of stabilizing things for most of Eastern China, but Japanese aggression still followed. In 1931 Manchuria was annexed by Japan, and in 1932 a skirmish broke out between Nationalist and Japanese troops in Shanghai. There were strikes and protests continuing both against Japan and the increasingly oppressive KMT. Many young intellectuals and revolutionary minded Chinese fled to CCP enclaves, and civil war returned to China in 1927. For the communist students across China and many urban workers, this was a very politically active time in their lives. Boycotts broke out nearly every year from 1925-1936 across China, usually directed at Japanese goods, sometimes all foreign goods. But with the focus on its cities, generally life for the urban elites who remained loyal to the KMT was good during this period. The communists generally began staying away from the cities in China after they realized their efforts failed there, and returned to the country, where conflict resumed. There was probably a feeling of malaise by many urban elites regardless due to Japan, but the increasingly modernizing China brought some nice luxury perks for those who could afford it. Especially in the cosmopolitan Shanghai, it wasn't uncommon to see wealthy Chinese driving cars, wearing fine jewelry and using perfumes to go out to the theatre. Even the poor urban workers caught a break from constant conflict.

In more rural areas, the military and ideological conflicts continued. peasants were picking sides as CCP agents and KMT troops began moving across the fields. The KMT ran several "encirclement" campaigns to root out communist influence, many of which ended in indiscriminate slaughter of civilians. Though for the most part these campaigns slowed down in the mid-30's, and KMT victory was all but assured. Things finally calmed down for a bit.