You may Force Quit from Activity Monitor.
close all Adobe apps if opened,
Make sure to end all Adobe processes like Creative Cloud , CoreSync, AAMUpdater, Adobe Crash demon PDAPP...etc
Applications > Utilities > Activity Monitor.
Then launch Creative Cloud app again and try to update.
Along with what is suggested above you can follow the article: Troubleshoot Creative Cloud download and install issues to get the issues fixed with Creative Cloud updates.
Let me know if it works or not.
Thanks a lot man. I didn't know about that Activity Monitor - very useful.