I'm on an iPhone can't see your pic so well. Depends on the event. I'm guessing here, but a luncheon would be like dress pants, nice top or shirt, guy might wear sports jacket. Go for classic stuff lbd (little black dress) for girl suit for guy for dinner.
I don't know, but you can call the country club hostess or host and ask about the dress code or for suggestions. You don't have to tell them who you are. I'm sure they get the question often. Don't be embarrassed to ask.