I am trying to run sudo apt-get update, but there are errors that I don't understand:
What does this mean, and how can I resolve it?
Thank you,
This is happening because there is no release for the version of Ubuntu that you are running. The simplest way to resolve this would be to remove the outdated repositories from the updates, at least temporarily.
To do this:
Open your "Software & Updates" application
Go to the "Other Software" tab
Remove the repositories that do not have a release:
Press [Close]
The system will update the repositories that it reads and then you should be good to go. If, in the future, there are updates to these repositories to make them compatible with your version of Ubuntu, simply check the boxes and update again.
Hope this answers your question.
