You can see, check and even book all the Shanghai-Beijing trains(https://www.travelchinaguide.com/china-trains/shanghai-schedule.htm) online here. I want to say something after you arrive in Beijing. If you want to take train to Badaling, you should take subway Line 4 from Beijing SOuth Railway Station to Xizhimen first and then walk to Xizhimen Railway Station, which is exactly Beijing North Railway Station. If you want to take bus, you should take subway Line 4 to Line 2 and get off at Jishuitan Station. Walk from Exit A for about 10 minutes to find Deshengmen Gate. Bus 919 there can take you to Badaling. Hope this make sense.