Orange is a small town and nice. It is quiet and peaceful. Nothing much seems to be going on there. When I was there, I noticed that there were not many tourists visiting the Roman Theatre and Roman Arc, even though I arrived during the weekdays. However, it is kind of charming and nice to walk around exploring the small lanes and alleys to see the French shops and way of life. I even saw the statue of the Count of Orange in the town square.
The Roman Triumphal Arch which was erected in 1st century BC is well-preserved. The Arc is a distance from the Roman Theatre and we had to ask for directions from the locals to look for it. It was located standing alone at a road junction.
Orange town is renowned for its Roman architecture; it possesses the best preserved Roman theatre in Europe, as well as a particularly fine triumphal arch, both built during the reign of Augustus. The arch, theatre and surroundings were listed in 1981 by UNESCO as a World Heritage Site. In 1869 the Roman theatre was restored and has been the site of a music festival. The festival, given the name Chorégies d'Orange in 1902 has existed annually ever since, and is now famous as an international opera festival.
You would have to pay a small entrance fee to the Roman theatre. It would also be good to rent an audio guide so that you will understand better the history of the Roman theatre. It was very interesting to see a real Roman theatre, and I managed to climb up to the highest point of the seating podium to see how the Romans would watched a play.
I am not sure about the night life on the weekend, but while I was there, there was not much of a night life. There were the occassional bars and restaurants that were opened but they tend to close early.