day trips out of Venice night time activity

Once you have done the islands, you should consider the Lido (can't recall the exact name). It's a beach resort in the area.

Another possibility is Vicenza for great architechture.

At night, I really like just going for a stroll. There are a lot of late night eating options where you can wine and dine until late and a few bars where you can hang out. The square also has cafes with small orchestras where you can eat, get a drink or just stroll through the square and freeload.

I really enjoyed Murano (glass museum, glass demos, glass stores, and gelato)and Burano (lace making and gelato). I actually stayed on Murano and day tripped to Venice. FYI: These two islands have no "night life". I enjoyed searching for the restaurant that was open for dinner (there are only 2 or 3 open at a time for dinner, and sitting at the tables along the canal people watching and people meeting (just the locals are there in the evening), drinking several glasses of Prosecco, and then maybe a Limoncello. I really miss that and have to go back soon.

Venice is not known for its nightlife. It pretty much shuts down. The best night time activity is wandering around and enjoying the beauty of the place.

The areas around Campo Santa Margherita and Campo San Barnaba have a nice collection of restaurants and bars to eat, have glass of wine, and people watch. But not a lot of nightlife in terms of clubs.