Since you've enabled the Universe repository, and it still does not work, that suggests that APT has not been updated to use the new configuration. (This can cause the problem you're experiencing even if it has been updated to use the new configuration, but has not been updated since other changes were made.)
I noticed you didn't mention running
sudo apt-get update. It's a good idea to run that before installing software on the command line. If you haven't run that very recently, try that, and then see if you can install the software.
If that does not work, then the problem is usually caused by a misconfiguration of your software sources. You could have only parts of the necessary sources enabled, or you could be configured to use software sources that are broken on the server (some mirrors might malfunction or go down), or software sources for the wrong Ubuntu release or for some other operating system altogether.
So, if running
sudo apt-get update doesn't fix the problem, take a look at the contents of
/etc/apt/sources.list. One way to view the contents of that file is to run:
If that doesn't clarify the cause of the problem, or you want help interpreting its contents or checking if they are correct, then please edit your question to include the ful output of that command (and also of