Welcome to Gaia! ::

Hajimemashite. Watashi wa Sutefani de, Nihingo o benkyou shimasu. Juugosai de, Amerikajin desu. Watashi wa Nihon ni ikitai.

Pleased to meet you. I am Stephanie, and I am learning Japanese. I am 15 years old and an American. I want to go to Japan.

To spell today- it's kyou~ in addition, if you say you want to go to the mall, you would say "maaruHE ikiTAIdesu." Use "he" (pronounced e) as the particle for a place when you're going, coming, or returning there. And it's "ikitaidesu" as you take the root of "ikimasu" - "iki" and add "taidesu". To say that you DON'T want to do something, it'd be "ikitaKUNAIdesu"- you take out the "i" of "tai" and put in "kunai" (like a knife! XD) --- In addition, to better conjoin the last two sentences "I have money. I don't have a car," it'd be good to put "but" in there- So you could either make it "Okanega arimasu. Demo, kurumaga arimasen" - or "Okanega arimasuga, kurumaga arimasen."

Doot doot~ totemo tsumaranai desuyo!! >_<

((It's actually 'kimashita.' You could also say 'Amerikajin desu.' (I am an American)))

Watashi mo Amerika kara kimashita. Eto... Eto... 'Maaku' ga Eigo de nan desu ka?

konban wa watashi wa meru hoshi desu 3nodding

Konbanwa. Hajimemashite? Neko desu! Dozo yoroshiku!

ええと、はじめまして。 私はアロヨです。 ごめんなさい、 少ししかわかります。
Eeto, Hajimemashite. Watashi wa Aroyo desu. Gomen nasai, sukoshi shika wakarimasu.

Good try, you have the general idea. I think I was able to get most of what you were saying. However it comes across as being very stilted and/or unusual. Here is how you could make it sound smoother and more understandable.

Technically, everywhere you used 'wa' could be considered correct, but it sounds very odd. Being the 'topic marker' it marks the word it comes after as the topic of the sentance. Sounds simple but really it's beastly hard >.> There are many many particles to choose from. So, since you marked both 'nihongo' and 'nihon' as the topics of the sentances, it sounds like this: "As for Japanese I am studying it." "As for Japan, I want to go" It is a very bulky way to talk, but it's hard the recoginize that when you aren't super familiar with the language. If you were saying the same things naturally in English, you would say "I am studying Japanese" and "I want to go to Japan" This makes YOU the topic (and if the topic is understood, like when the topic is the person speaking, it is often dropped to make the sentance more concise). In the first sentance, Japanese becomes the direct object because it is what the verb is acting on. So a much smoother sentance is: "Nihongo wo benkyou-suru" (wo is the direct object particle). In the second sentance, Japan becomes a specific location you are describing instead of the topic. So you use the location particle 'ni' to descibe it. So you would say "Nihon ni ikitai"

Also, do you mean to say that your favorite food is fish AND you love wasabi, or your favorite food is fish BUT you DONT like wasabi? Because what you really said (i think) was "my favorite food is fish. It's great! But...I love wasabi" That doesn't make sense to me.

Other than that, just spelling mistakes: sakano->sakana, tabemano->tabemono, daisuke->daisuki