Ways to use MandarinChinese tourists cannot speak Spanish (or even English) and Spaniards cannot speak Mandarin. You will have plenty of customers.
Little hint for you. If you are interested in making money and would like to work with better quality customers, forget the tourists and get into business translation / communication. Catalonia is a very rich area and they have all kinds of business connections to China. Why would you want to translate for bunch of Chinese farmers when you could be part of some interesting business trip to China or in Spain?
I would recommend to you to take classes in PR or corporate communication. Masters degree in business comms and Mandarin, Spanish and English skills is a winning combination for the future.