I just moved from Ubuntu to Debian 10, and I haven't been able to install wget. I tried
sudo apt-get install wget But recived this message:
This may mean that the package is missing, obsolete or only find available from some other source. The wget package is not available, but some other package references to it. 11 Answer
This happens if you boot a live image:

Fix it by running sudo apt update to update package information first.