By default ubuntu 20.04 does not have VIM or GVIM installed.

If you only have command line but not a DE like gnome , you can just install VIM

sudo apt install vim

How to install gvim in Ubuntu 20.04

sudo apt install vim-gtk3

vim-gtk3 is a version of vim compiled with a GTK3 GUI and support for scripting with Lua, Perl, Python, Ruby, and Tcl .