Possible meanings are 1) God was referring to one human, the man, or 2) God was referring to humans in general, so this would mean the man and his wife. Even if God was speaking about one person, what he said applied to both of them.
Here "good and evil" is a figure of speech that refers to both extremes and everything in between. See how you translated "knowledge of good and evil" in [Genesis 2:9](../02/09.md). Alternate translation: "knowing everything, including both good and evil" (See: [[rc://en/ta/man/jit/figs-merism]])