enable sudo

login as root:

su -

add your user to sudo group:

gpasswd -a user sudo

update system

update your system to latest:

sudo apt update && sudo apt -y upgrade

enable flatpak:

sudo apt update && apt sudo -y instal flatpak

configure gnome software flatpak plugin:

sudo -y apt install gnome-software-plugin-flatpak

enable flatpak repo:

flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

install developer essentials tools:

sudo apt -y install build-essential

install gnome extensions manager:

sudo apt -y install gnome-shell-extension-manager