Hello, I'm planning to go to Yuanyang on the 17/11. We arrive to Kunming airport at 15:00

Yes, you can go there the same day. As I know, many visitors would like to hire a local car to Yuanyang from the airport. It costs CNY 1,200-1,500 for a single trip and you can share it with other visitors.
As for camping, I don’t think it’s a good idea. Since there are many rainy days during this month, you’d better find a hotel.