I'm confused as to which type to apply for. Tourist with multiple entry? Transit type?

Hi I'm a us citizen in Paris as a tourist. I would like to fly to China next. I plan to fly one way to Beijing and then travel by train to Hong Kong. I would then like to travel back into mainland China and take a train to Vietnam. All of this over the course of 1 month. There is a Chinese consulate here in Paris where I think I can apply. Can I apply from Paris as a tourist? I was going to buy my plane ticket today but I don't want to spend the money if this is impossible. Any help with my questions would be appreciated.