The distance between these two cities is about 1,000kilometers. So, you could fly from Changchun to Beijing directly. Or, you could take the express trains running between them, which just take abotu 6.5 hours on the way. Well, for the real-time flight and train's information, please refer to: https://www.travelchinaguide.com/china-flights/
https://www.travelchinaguide.com/china-trains/