Be careful, but you can carry these exercises out on almost any computer, safely. You may be deleting files and directories, hence the warning! Do not practice on a production system!
If you are familiar with VMWare Workstation or Hyper-V, you can stand up some VMs to carry out this work, this is always the preferred approach.
In Unix, your home directory will be /home/username
Throughout these notes, adapt my instructions to wherever your home directory actually is.