Both my parents are citizens. Does that make me a citizen automatically? How do I bring my fiancé to the U.S.?

You are eligible for derivative citizenship and should apply on Form N-600 with the nearest USCIS Field office, with the appropriate filing fees. If approved, you will be scheduled for a naturalization interview. As far as your fiancé, I recommend that you file after you obtain your citizenship. That way, you can bring him on a K-1 fiancé visa.