ubuntu 20 gnome reinstall

My system ubuntu started getting broken recently. I noticed this first when I first accepted bootload update from Hewlett Packard (my machine is HP Z workstation). My keyboard (tilda, ctrl, alt) started acting up and couldn't type Korean. Recently I added VMware for a testbed platform I am learning from Udemy. Now my gnome-terminal couldn't be started. In short, I noticed some issues as follows; apt_pkg, no module named apt-add-repository not working Is there any way to reinstall (no format) as explained here [login to view URL], which should be taken as an example as I am not sure if their suggestion would help me to achieve restoring my old system. my budget: usd 30 your task: to restore my old system by fixing issues i have; documentation of your progress