You said you downloaded the .deb file \"in download files.\" Assuming this means you downloaded it to your Downloads folder, that means it's located in /home/collins/Downloads rather than /home/collins.
I also have the exact same problem: Adobe DC simply won't open. I waited for a few months and then downloaded the latest version of Adobe DC, but it still does not work. I have tried both repairing and reinstalling, but nothing works. 1e1e36bf2d