The history of Japan is fascinating. There is evidence of the first habitation in Japanese archipelago in prehistoric times.
How interesting.  How long has Japan been around with the same native people?
I'm not sure but during the 4th century and the ninth century, a centralized government was created.
That is awesome.  Can a lot of Japanese people trace their ancestry that far back?
They probably can. Around 129 million people are of Japanese descent and about 125 million of them live in Japan.
How do they display their culture whether it be in their homes or public spaces?
I'm too familiar with that but I do know the japanese language is related to the ryukyuan languages.
Do people still speak the Ryukyuan language?
Ryukyuan languages
The are the indigenous languages of the Ryukyu Islands, the southernmost part of the Japanese archipelago. Along with the Japanese language, they make up the Japonic language family. The languages are not mutually intelligible with each other. It is not known how many speakers of these languages remain, but language shift towards the use of Standard Japanese and dialects like Okinawan Japanese has resulted in these languages becoming endangered; UNESCO labels four of the languages "definitely endangered" and two others "severely endangered".
Overview.
History of Japan
The history of Japan covers Japan and its relation to the world. It is characterized by isolationist, semi-open and expansionist periods.
Please see the era classifications for details of each era.
The very first human habitation in the Japanese archipelago has been traced to prehistoric times around 30,000 BCE. The Jōmon period, named after its "cord-marked" pottery, was followed by the Yayoi in the first millennium BC when new technologies were introduced from continental Asia. During this period, the