So I'm not writing this to be a dick but rather to explain to you why you are not going to get a super sweet, long winded 'official' askhistorians answer to the question.

I. Format/wording

Your question asks for the 'first' of something and any time some one asks that it is bad news because chances are we don't know the 'first' usually unless you are talking specific modern advancements. What can be provided are earliest historical examples.

You are also asking about a "civilization nation". Simply put that is not a thing. A nation is simply a large group of people who share a common language though in modern parlance it usually is used to refer to a 'nation State' which is also a very modern idea. A civilization is also a nebulous, imprecise term but I would define it as a set of cultural characteristics, language, geographic area, and state systems. The Hellenic civilization is an example of a civilization whereas Athens and Sparta are examples of City States within that civilization.

II. The question itself is kind of bad.

You ask for an example of a group of people that didn't "like" to go to war. I would argue that nobody "likes" to go to war but there are groups of people who were historically more hawkish. You could have phrased it by asking if there is evidence of a group of who never engaged in warfare.

Also what qualifies a group of people as "peaceful"? Its really difficult here to suss out what it actually is you want to know.