how long is it from guanzhou to chengde? and what are the available means of transport and the whats the price

There is about 2400 to 2500km between the two places.
There is no train between the two places. If you want to use train, you need to transfer in Beijing.
In my opinion, you can catch a flight to reach CD directly. The Air China and Hainan Airlines operate the flights between the two places. The flight takes about 3 hours. If you can book the tickets in advance, you may get a large discount.