For the files the easiest way would be to use the file syncing. Sign in with the old account and download the files to the Creative Cloud Files folder. Then make a copy of these files. Now sign in with the new account and put the files into the new Creative Cloud Files folder. Your files will sync with the new account.
For Libraries you can go to https://assets.adobe.com/assets/libraries and select Send Link for each Library you want to transfer. Then go to the public link for that library and select Save to Creative Cloud. A copy of that library will now be in your new account.
I know this is a nearly ancient thread, but I think the solution is still accurate.
I've been able to move my files and libraries over, but what about Mobile Creations? When I select multiple files or projects, the only options I get are copy (which means duplicate here) or delete. Do I need to share each one individually?