Hi. You need to do this for ethernet :
ifconfig -a
sudo ifconfig eth0 up
sudo dhclient eth0
For wifi it’s this :
sudo nmcli dev wifi connect ESSID_NAME password ESSID_PASSWORD
If you would like to install a desktop, then use this :
sudo apt install lxde (installs only lxde desktop)
sudo apt install ubuntu-mate-core && sudo apt install ubuntu-mate-desktop (to install ubuntu mate desktop)
sudo apt install lubuntu (to install Lubuntu desktop + lxde desktop)