Until this moment, I have installed packages solely on Ubuntu. Now, I am trying Kali Linux,namely
uname -v #1 SMP Debian 4.9.18-1kali1 (2017-04-04)
A friend, who unfortunately knows less about Linux than me, told me of his problem to install even basic Packages on another Debian distro, though this seems odd, since I heard, that the Repository of Debian is far more bigger than that from Ubuntu.
apt install kdenlive apt install audacity apt install blender
The fruitlessness of my striving made me modest and so I tried
apt install cowsay
But even this could not be installed, could you give me an advice how to deal with this?