The word "now" is used here to mark a stop in the main story. Here Luke tells background information about the people in Berea and how they were willing to listen to Paul and examine what he said. (See: [[rc://en/ta/man/jit/writing-background]])
These "well-born" people were willing to think more objectively about new ideas than other people. Alternate translation: "more open minded" or "more willing to listen"