Kali Linux 2020.1 not booting in GUI after installation

[Rohan0]

Few days ago, i installed the latest version of Kali Linux 2020.1
After installation, it is unable to boot in GUI. All it shows is a giant terminal covering the whole screen.
i even tried using commands such as-
startx
sudo startx
gdm3
sudo gdm3
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install gnome
and some more commands along the same line.

all i get to see is either 'Operation not permitted'
or 'Package is unavailable....bla bla bla'

if anybody has any recommendations on how to bootit up in GUI, it will be good.
help me out in this.
your effort is appreciated. Thanks.

[Hintax]

The same thing happened to me. fix it by updating the repositories with the sudo nano code /etc/apt/source.list and then installing the gnome