'ouh la la' has no real signification in French. This isn't a proper word, but an interjection used to express (depending on context and of the tone of the voice) admiration, awe, pain or other...
La is "the" in french. It is one of three definite articles, la, le, les. La is used for feminine nouns, le is used for masculine nouns, and les is used for plural nouns. Oui (pronounced "Wi") means...