Unix/Linux System
If you do not have any Unix/Linux systems, we would suggest download the virtual machine together with the Unix/Linux system on your current OS.
For Ubuntu 20.04 on VMware workstation:
https://theholmesoffice.com/installing-ubuntu-in-vmware-player-on-windows/
For Ubuntu 20.04 on Oracle VirtualBox:
https://brb.nci.nih.gov/seqtools/installUbuntu.html
If you are not familiar with Unix/Linux systems, please go through the resources listed below to gain knowledge of command-line basic navigation in these operating systems (through terminal/console, bash or c shell).
One of a good links is this one curated by University of Surrey:
http://www.ee.surrey.ac.uk/Teaching/Unix/index.html
Another good one is this one from the ubuntu distribution (including some history):
https://ubuntu.com/tutorials/command-line-for-beginners#1-overview
and this one (although a bit more advanced):