I suppose this is a pretty broad question, but I'm not looking for anything super exact except some general knowledge on how the Chinese viewed the Korean war, from any perspective available. How did they see it? How did their soldiers and civilians see it? How were the UN/South Koreans viewed during the war and what about the North Koreans? The war is rarely mentioned even from the US side and I've almost heard nothing from the other - pretty much any information would be appreciated.
Edit: As noted by /u/Fusion-, replace all below instances of "Kim Jong-un" with ”Kim Il-sung".
I don't have the expertise to give you very precise answers to this question, but I can give you some background on China's relationship with Korea which is very indicative of their perspective on the war and the motivating factors behind it.
By the time the Korean war was in full swing, China was a communist nation - it had just wrapped up a major civil war between the communist and nationalist factions who had been struggling for control for a few decades prior with the communist faction coming out on top. Given that the North Korean government was a communist institution with support, resources, and personnel training from the USSR, China was a natural supporter of the North as well.
However, the basic communist link between NK and China is only the tip of the iceberg. The communists of China and the leadership of NK shared a deep relationship that stretched back to before the formal outbreak of WWII, to the early aggression from Japan just before the start of the Second Sino-Japanese War, c.1935ish. The Japanese were working at building an empire and had annexed Korea and the northern region of China, Manchuria. Both were being exploited for labour and raw materials.
The Chinese Nationalist faction, the KMT, had the upper hand in the struggle at the point, and had a more centrally organized military that engaged Japan in more traditional warfare. The communists, on the other hand, the CCP, didn't have the manpower and resources for that, and the Japanese threat had created a truce with the KMT that was fairly fragile, so they kept it small-ball: small guerilla units in a relatively disjointed network. Korea had no formal opposition whatsoever. It was much more firmly under Japanese rule, so there wasn't a Korean army fighting on battlefields with the Japanese.
Instead, dissident Koreans would find their way to Manchuria and join up with CCP guerilla units. Bruce Cumings estimates that in fact most CCP guerilla units may have been as much as 90% comprised of Korean dissidents. This included Kim Jong-un, who was absolutely legendary as a guerilla warrior, and almost all of the men who would become his inner circle in North Korea.
You can see where this would form a strong link. Kim and his supporters virtually learned Communism at the knee of the CCP and fought alongside Chinese communists against a common enemy. This also got the attention of the USSR, and as WWII wound down, they brought Kim Jong-un to Russia to prep him for leadership of the new provisional government they wanted to establish in Korea - the government that would become the Democratic People's Republic of Korea, or North Korea.
The connection was intensified after the installation of Kim's government of North Korea. While Russia and the U.S. had what essentially amounted to an international dick-measuring contest trying to decide whose provisional government would be recognized as the official government of a new independent Korean state, the CCP and the KMT were having open civil war for control of China - their peace hadn't even lasted the duration of WWII. And Kimg Jong-un was helping. There were 50 000 soldiers affilated with North Korea fighting on the CCP's side in the Chinese Civil War, and when the war wrapped up in 1950, Mao sent them back to North Korea, now seasoned combat veterans armed and supplied by the CCP. That move was a big deal - American intervention later that year would mark the 'official' start of the Korean War, but there had already been serious hostilities between North and South Korea going on for years - basically since they formed in 1946-7. Sending 50 000 troops back to North Korea armed and ready for war was a pretty strong statement of support for NK.
China essentially couldn't help but be involved in Korea. They had a sense of shared trial with North Korea, who were essentially seen as a total rejection of Japanese imperialism, whereas the southern government used the Japanese system as sort of a foundation and model for how they were structured and some of their policy. That was the heart side. On the head side, South Korean victory in Korea meant American victory in Korea, and they definitely didn't want that. America saw Korea as a war of containment, and of stopping the spread of Communism in Asia while ideally establishing their own sphere of influence in Asia by propping up a capitalist establishment in Korea - they'd essentially try this again in Vietnam. That's like a declaration of war on the ideology that China had literally just a fought a war to establish. If South Korea came out on top and Korea reverted to a fully capitalist state supported by the US, then suddenly Taiwan, home base of the KMT's government-in-exile, suddenly becomes a likely prospect for the next embattled capitalist state that needs a helping hand from the US.
As I said, my expertise isn't sufficient to address the social side of this conflict - how individual soldiers or citizens looked at the war. But I hope this helps you see what the history pushed the institutional view toward, to give you some background that someone with stronger expertise can fill in with some good primary sources. China was in some ways obligated to support 'true' North Koreans against the South because a sort of sense of kinship won by North Korean support of the CCP since before there was a North Korea. Practically speaking, they had little choice in the matter as well, as opening the door to an American 'puppet state' in South Korea meant potentially empowering Taiwan and reigniting a Civil War that less had a resolution so much of a cessation of hostilities, and they needed to protect their own interests in the Asian sphere of influence, which was of increasing importance in the global geopolitical theatre.
/u/The1Man has given a very good perspective on the Communist party's point of view. I'd like to talk a bit about how the war was presented to ordinary Chinese.
The official Chinese name for the war is "The War to Resist America and Aid Korea." This alone should tell you a bit about how the war was framed by the Chinese Communist Party. People in the US were told that the purpose for their intervention was containing communism. People in the PRC were told that it was pure unabashed Western imperialism. This is not unreasonable from a Chinese perspective. At this point, China had suffered from imperialism for almost a century. So when western forces were fighting an ideologically allied group in a neighboring country and were getting close to the Chinese border, it wasn't particularly difficult to "sell" the war to the Chinese people.