When staying at the airport, options are very limited.
Eat, drink, watch airplanes through windows (airside).
WN has the greatest share in pax at BNA; other carriers often bring their regional a/c, mainline-a/c can be seen, too, but AA B738 is the biggest scheduled, daily visitor.
Carpe diem ! Life is too short to waste your time ! Keep in mind, that today is the first day of the rest of your life !