There is loads of walks/hikes around the lake, springs and mountains you can do, we have massive shopping centres, a few cinemas, loads of places to eat. Other people would be the best people to tell you about the night life.
Traveling in China is reasonable, from 180RMB one way to Beijing (from Jinan) and I think it was 400 RMB one way to Shanghai. Both are within distance to go away for a weekend. You can either do an overnight train to shanghai or do it within 4hrs, we have done to overnight train and I would recommend it (it’s cheaper and for sure an experience). Beijing is about 1.5hrs away.
There are always new areas to explore and new experiences around each corner. The current teachers in all of the areas are very welcoming and will show you around. Often the teachers go explore and travel together to the different parts of China. M.E.F. also organizes some events and gatherings for the teachers throughout the year.