Fruta fina literally translates to "fine fruit." However, in Dominican slang, it's used to describe someone, usually a woman, who acts conceited or thinks too highly of herself, often due to her looks or social status.
In this song, Ramon Orlando repeatedly tells someone, "No te creas fruta fina" (Don't think you're fine fruit), advising them not to be arrogant or stuck-up. It's a colorful and culturally specific phrase that adds a unique flavor to the lyrics.
Ramon Orlando's "Fruta Fina" is a fun, playful song where he's giving some blunt advice to a young woman. He's basically telling her to stop acting like she's a "fruta fina" [fine fruit] – meaning she's not as special or high-maintenance as she thinks she is! He reminds her of a time she embarrassed him at the Malecon and suggests she shouldn't expect everyone to treat her like a queen.
He's urging her to be more realistic about finding a good partner. He tells her to "aprovecha el tiempo ahora que estás bueno y jovencita" [take advantage of the time now that you are good and young] and look for a good, serious man who will take care of her, instead of just someone who takes her to the Malecon. He even says he's "de retirada" [retiring] from trying to win her over, implying she's missed her chance with him and needs to wise up before it's too late!