"Nice to meet you, I am John."
Think of hirigana as phonetic spelling of words (think: jin. It has its own character, but can be spelled out in three characters as well). Adding special characters to already existing symbols changes the way the original is pronounced. Look at TO. When the little " is placed next to it, it becomes DO. I hope this helps a little and I haven't confused anyone more than they already are. I took on trying to speak Japanese like 30 years ago, but never learned to read or write kanji. That's all under the bridge now, and I'm starting over. Just take baby steps and you'll get there. I'm right there beside you all making the same mistakes.
Yoroshiku onegaishimasu is more of a "please be kind to me" and it doesnt replace Hajimemashite which means "first time", literally telling someone its the first time you meet them.
The common pattern is: Hajimemashite, watashi wa John desu, yoroshikuonegaishimasu.
Nice to meet you, I'm John, please be kind to me.
I know this is an old comment but maybe it will help someone else: You don't use honorifics in reference to yourself. Because the sentence is "I am John", you never use -san to refer to yourself (from what I've been told, it's seen as stuck up or being full of one's self)
This is kind of a late reply, but in case it's still useful: はじめまして isn't hello, it's nice to meet you (literally, 'for the first time', the implication being sort of 'this is our first time meeting, so let's introduce ourselves').
It's not necessary to use 私 or anything else that specifies that you're talking about yourself unless you really want to emphasise you're referring to yourself. Japanese is a very context-dependent language, meaning if something goes without saying it typically gets left unsaid. But yes, your sentence is grammatically correct. Just keep in mind that it's こんにちは, not こんいちは (you have to press the N key 3 times) and it's not really used in introductions, so best stick to はじめまして.
Both are phrases you might utter when you are introducing yourself. It is just that "hajimemashite" is used the very first time you meet someone, and yoroshiku can be used during subsequent times. In fact, you can use both phrases together. IIRC Duo will accept Yoroshiku when it asks you to translate the English.
Hajime (はじめ) means "first." So, you only use it when you meet someone for the first time. よろしく means, "Be nice to me." The latter is a common greeting. There are often cultural nuances behind greetings, like the English, "What's up"- the sky? And the Chinese, "Ni chi fan le mei you (have you eaten)."
です is a copula and roughly translates to the verb "to be". It is used in is/am/are sentences when equating one thing with another. In this sentence an implied "I" is equated with the name "John", "I am John"
人 is a kanji that means "person" and you would only use it in the context of talking about people.
Alone 人 would just be the noun "person/people",
それは人です - sore wa hito desu - that is a person "that (thing) = person"
その人は静かです - sono hito wa shizuka desu - that person is quiet
as a suffix it can be a nationality or ethnicity,
日本人 - nihonjin - Japanese "Japan-person",
白人 - hakujin - Caucasian "white person"
attached to a number it is a counter for people.
一人 - hitori - one person 三人 - sannin - three people
When a kana is smaller it means it combines with the one before it, rather than "Ji-yo" it sounds like "Jo" and you get these kana by typing it as '"jo"
Ka+ya = "Kya" きゃ or キャ
Ri+yu = "Ryu" りゅ or リュ
If you want them by themselves you can add an l or x before the sound to make them smaller
"xya" or "lya" = ゃ / ャ
"xyu" or "lyu" = ゅ / ュ