Of course, I personally think that I must have more than half a year's long-distance running experience.
And it's best to start with a half marathon.
There are more and more competitions in China every year. In 20 13, there were 33 marathons in China.
If you are interested, you can search official website Marathon, and the training plan can search "Adidas Marathon Training Plan" (personally, it is very systematic and professional).