The most popular version is the King James Version, or KJV Version for short. Many English words are different from now. But older people like to watch this version, because it rhymes and cadences, so it can best reflect the beauty of English. But it's not good for learning English. For example, you are you now, but it can rhyme with other words.
Both the Old Testament and the New Testament can be read, but the Old Testament is more difficult to understand. The New Testament is simpler.