はじめまして！

こんにちは。　（わ　ではなく　は）です。読み方はwa なのですが・・・。

私の名前は　ゆき　です！

はじめまして、ＰＡＣＨＡです。
どうぞ、よろしくおねがいしますｍ（＿＿）ｍ

チアゴさん、こんにちは！

Please be careful to type "Konnichiha", need to have two "n" to make it "n-ni : んに", otherwise it becomes "n-i : んい".

And last letter "わ" is difficult and complicated.
Pronunciation is exactly "Wa". However when you write in letters, you need to use "Ha : は" instead of "Wa : わ"．

In Kanji Character, "こんにちは" is wrote as "今日は", it means "Today IS...".
Long time ago, Japanese people was greeting "Today is good day!", and eventually people start to shorten the word to "Today IS".

We use "は", because it stands for "IS".

The other sentenses are perfect!!

I hope my explanation make sense to you...
頑張って！！

こんにちは！　はじめまして。
私の名前はゆみこです。
よろしくおねがいします。