Chengdu to Mianyang

I am flying into shuangliu airport on China Southern. Plane arrives 21.25pm. I should clear customs by 22.00pm. From the internet it appears that the last train to Mianyang has departed already. I was thinking of staying at a hotel close to a station on the Mianyang line and catch an early ride the next morning. 2 questions: First how and where do I buy a ticket from the airport to downtown hotel and secondly, how and where do I buy a ticket to Mianyang? I do not speak Mandarin.