かうかった　はん きょ　おれ　わ　飼う褐炭　にほんご　はん。しかし　にほのご　よく　花ません

Kanji Does Kanji really affect a word or a sentence greatly? If いちばん = most does 一番　have a different meaning?

Preparation Looks like I'm going to Tokyo in a few months thanks to some activity organized by my University. The only problem is, I still can't read Kanji and my vocabulary is still in need of supplying. Nevertheless, I'm excited. Daily practice: Romaji : Kimi wa oshiete kudasai (Im not sure if it makes sense.) Hiragana: きみわおしえてください

First I don't really know what to write. I am already fluent in English, but I am as good as a toddler, wait, no, even worse, in Japanese. I can't even write anything, despite knowing a handful of Hiragana characters. I don't even know how to use Kanji, or what kanji really is. Is a Kanji character a word or a syllable? Is it used to signify the beginning of another word? I am yet to know that. I don't even know if this is correct: おまえわいいです