There are no direct trains between the two places. If taking train, you can transfer at Nanjing or Wuhu city. However, it will takes around 60 hrs in total on train. Thus, you are advised to take a flight to Jinan first, and then take a coach or train to Dongying. For the flight info., you can check on the page: https://www.travelchinaguide.com/china-flights/