沖縄県 (okinawa-ken), which is "Okinawa Prefecture", omitting the last Kanji 県 (ken) makes it 沖縄 (okinawa).
These are the characters for "Okinawa"
You don't, you spell it with katakana.
foreign names are written in katagana not kanji
The Japanese word for culture, "bunka", is written as 文化 in Kanji.
Good fortune in Kanji can be spelled as "福" (fuku).
羽の矛
Okinawa is a Japanese Island and also a Japanese Prefecture. The cultural differences can be compared to that of Hawaii and Mainland USA. There are different dialects, dances, religions, different kanji, less uptight feeling.
The proper name for the island in southern Japan is spelled Okinawa.
兄弟分 - pronounced "kyoudaibun"
神山 樹 are the three kanji characters for Kamiyama Itsuki.
Kanji - 侍 Hiragana - さむらい
Since you wrote Dell in uppercase I take it you mean it as a proper noun, then it would be デル /de ru/. And it's in katakana not kanji, since it is a foreign word.
You spell like... kyouba(in Romaji) - 競馬(in Kanji) - きょうば (in Hiragana)