Firstly, there's something I'd like to correct. It's ganbatte and not kambateh, if the meaning is supposedly good-luck. If it's not, I can't really help you. In hiragana, it'sがんばって, or in katakana, ガンバッテ. Kanji would be 頑張って, just a slight difference from katakana. I hope I helped = (
バレリー
You may write it as: 中心
植物。It means "plants" in Japanese.
家族
職人
レア Rea
ガブリエル (Gaburieru)
ジェームス(zyeemusu)
The only surefire way to remember the Japanese characters is to write them, write them, write them. It's how the Japanese do it. Fill notebooks, use flashcards, and constantly refresh yourself on what you've just learned. Try ten characters a day!
盆栽
To write in Japanese, you will need to install a Japanese IME on your computer.
The hiragana (basic Japanese characters) is とも, and the most-common kanji (characters originating from China) is 友.