はじめまして。シンガポールからのクロノンと申します、あだ名ですけど...本名はちょっとな　^^;
[Hello. I'm Kronon from Singapore. That's my nickname of course, my real name's a secret ^^;]

はずかしいっすが、今年は２４才です。
[Kinda embarrassed to say this, but I'm already 24 this year.]

いやぁ...もうちょっとおじさんになちゃったの年齢だね
[ *sigh*...just a bit more and I'll become an uncle(Note : it's a Japanese thing ya know, when younger peeps call you 'big brother' and of course...'uncle' when you're even older...)]

高校時代の時に２年間ぐらい日本語を勉強したんだけど、あまり時間がなくなりますたから、あとで自分で色んなところから自習です。
[During my high school days, I studied Japanese for about 2 years, but found that I had no time to continue, so later on I just studied on my own from various sources.]

マンガとか、アニメとか、そしてテレビ番組も。
[From mangas, animes and television programmes.]

今はちょっとメガネの三城の店で働いています。
[Now I'm working for a bit at Megane no Miki(Optique Paris Miki).]

結構日本人のお客様がいますから、本当にいい実習のバイトです。
[It has quite a number of Japanese customers, so it's a really good part-time job for hands-on pratice.]

日本人のスタッフも大変お世話になりました。いつも私に日本語を教えたんだ。
[The Japanese staff there have also taken good care of me. They always teach me Japanese.]

でも私の日本語はまだめちゃくちゃですから、もっともっとがんばらなきゃ。
[But my Japanese is still pretty messy and I'll have to work a lot harder.]

どうぞ宜しくお願い致します <(_ _)>
[Best regards]

あっ、そしてここから英語で... ^^;
[Ah, I'll speak English from here...^^;]

Notes :
For first-time introductions, Japanese people usually use 「名」と言います([name] to ii masu) or 「名」と申します([name] to moushi masu) to be even more formal. 私は「名」です(watashi ha []name] desu) might be a little too straight-forward. But of course, as with everything Japanese, it's pretty dependant on the situation.

Likewise, 宜しくお願い致します(yoroshiki onegai itashi masu) is a more formal version. But this, maybe, is only used in more formal situations. It's used a lot in companies, like sending emails/talking between company employees, to other company people, etc.

*Humble Form*
言う　→　申す
する　→　致す

As you can see, I mix up a lot of formal/informal forms during my normal Japanese conversations, which is why I said that my Japanese is pretty messy.

こんばんは。(konbanwa. - good evening.)
はじめましてみんな。(hajimemashite minna? - how is everyone?)
私はドーグラスです。(watashi wa doogurasu desu. - I am douglas.)
十五歳です。(25さい）(juu go sai - I am 25 years old.)
どうぞよろしくおねがいします。(douzo yoroshiku onegaishimasu. - pleased to meet you.)
お元気ですか。(ogenki desu ka? - how are you?)