English has more than one use for the word "first". For example: - First, we asked our parents. (=at the beginning) That's the kind of expressions you would only use 最初 for, which is pretty obvious from the kanji it uses. As far as I know 一番 and its variants mean "first" as a number and also "the best". 最初 is also used as "at the beginning/ the one in the beginning/ first time" and so on. A few good examples from Tatoeba: 彼女は最初その馬が気に入らなかった。~ She did not like that horse at first 私が最初に行きます。~I came first (I was the one who came first) 最初の信号を左へ曲がって下さい。~At the first traffic light turn left.

元の英文とGoogleで翻訳された和訳（日本語訳）を示してください。 Show me your original English sentence and its Japanese translation by Google.