First of all, there is no direct bus from Liuyang to Nanxian. You can take a bus to Changsha first, note that it is the West Railway Station. The departure time is also very early. According to the bus timetable, there are no buses after ten o'clock, so you should start earlier. If you can't catch up, you can go to Yiyang first, there are many trips. Then it is also very convenient to go from Yiyang to Nanxian.

Then, I’m not sure about the time. It should take you about four hours. This is assuming you get into the car successfully.

Finally, Nanxian County is right on the edge of Dongting Lake. You can go to see Dongting Lake, take a boat ride (there used to be one), or you can go to Huarong opposite to have fun. Go to Nanxian County This is Maocao Street. It was very lively when there were ferries in the past.

Lastly, I hope you can catch the bus and have fun.