"I came to like it" is more like 好きになった or 気に入るようになった. "I got to like it" is a bit strange, but it could mean 好きじゃなくてはいかない or 気に入らないと駄目. "You gotta love it!" is something you might hear. It means that you can't help but love it. 気に入らない事は無理

Hey, this is really good! Almost perfect! I'd just change one thing. I had to look this up:「are working days」か「is a working day」のどちらが正しいかと調べました。すると、これ：
http://gtotd.blogspot.com/2007/06/not-only-but-also.html
I think I will recommend this:
"Not only is today a working day, but so is this Saturday."

I love the "No!!" and then I laughed when I saw it was 「ガーン」!  Another good choice would have been "Ouch!"

Last comment: if you use the = sign, we won't know how to pronounce it. Try this:
"...a public holiday called Shuubun No Hi, which is Japanese for Autumnal Equinox Day, ..."  

Bad Autumnal Equinox Day

 

Hi, everyone. In Japan, today is a public holiday called "Shuubun No Hi” (=Autumnal Equinox Day), but we had to work, because it's a working day in our company. In addition, we are supposed to have a workshop tomorrow. I fainally finished my powerpoint at 10pm. Not only is today a working day, but so is this Saturday<strike>, are working day</strike>... No!! Anyway, I'll get through tomorrow!!
Well, bye^^

みなさん、こんにちは。今日は日本では”秋分の日”という休日ですが、私の会社では出勤日となっているので会社に行かなければなりませんでした。しかも、明日は研究発表会があります。夜の10時にやっと資料を作り終えました。今日だけでなく今週の土曜日も出勤日です・・・ガーン。とにかく明日は頑張ります！！
ではさようなら。

I say hi from Japan!

I would like to exchange our languages to improve our language skills with each other while having fun. That sounds nice, doesn't it?

Yeah! That sounds really nice! Let's do it!

Really good. Just a few corrections:

Training course

Hi, everyone. I belong to the R&D dept. in our company, and there are about 25 people in the dept. Most of the R&D members<strike>,</strike> were on a training course, generally about how to control <strike>the</strike> quality. (「about quality control」はもっとスムーズに聞こえます。）It went from 9am to 6pm, and was too long and tiring... After <strike>the</strike> lunch, we occasionally had noded off a bit, but had never fallen asleep. It seemed just for the freshers, but it became a nice opportunity to remind us of the freshers' feelings, I think.^^（「freshers」って何ですか？）
By the way, we are supposed to have our own workshop <font class="Apple-style-span" color="#FF0000">in two days</font>, but my powerpoint is not finished, yet. So I'm worried about when I will <strike>have</strike> finish<strike>ed</strike> it^^; Therefore, I need much more sleep tonight!! Good night^^

明後日＝in two days それか the day after tomorrow
明日の後のいつか＝sometime after tomorrow

watashi wa adorarin desu. わたしはアドラリンです。

First notebook entry: Introducing myself

中国語は知りませんが…

Hi.
As you know I want to learn Mandarin and I am looking for a language exchange partner for it.
I traveled in some parts of China last year and learned some words in Chinese, so I understand easy words and sentences when I look at or listen to Chinese.
But I don't think my vocabrary is enough to communicate in Chinese.
So if you speak English, please contact me and teach me Mandarin, and then I'll teach you Japanese in return.
Thanks!

すごい！英語はほとんど自然い聞こえますよ！

An incident is something that happens. Maybe someone made it happen on purpose. Or maybe it was an accident. An accident is something that happens, that nobody did on purpose. An accident is a type of incident.