The beginning of the Yayoi Period was approximately 300 BCE.
Life in Japan was increasing at its fastest rate during the Yayoi Period. It's one of the earliest periods of history in Japan that we know about! You should look it up, if you don't already know about it.
The reading for this word is an exception but it's the same in Japanese as it is in English. So if you just remember it's Yayoi (やよい) in English, you'll remember the Japanese too!