There is loads of walks/hikes around the lake, springs and mountains you can do, China has massive shopping centers, cinemas, loads of places to eat.
Join sports and fitness, get a pet, or do as many do and take up learning Chinese.
Massages are also common and relatively cheap.
Other people would be the best people to tell you about the night life in the specific cities and popular areas.
Traveling is also extremely easy and relatively cheap. Every city has some special thing to see, do or eat.