I installed Ubuntu on my Chromebook following the guide here. I am still a beginner on using Ubuntu so all I could tell once it started is that it came almost "naked" (without several programs that usually come preloaded with Ubuntu). I tried opening the terminal and for example
sudo add-apt-repository
is not recognized. Several other commands are also not recognized. What is a good way to install all the programs like LibreOffice and a nicer terminal (the only thing I have right now is a terminal called XTerm) along with having all the commands like add-apt-repository that I usually use?