In the terminal
mkdir makes a directory in windows directories are called folders.
~ is a shortcut for your home directory.
Each directory is separated by /
mount is a command to attach parts of the file system
So I am saying make a folder and attache the iso to the system at that folder.
mount -o loop journey.iso /home/sydney/targetfolder
then click into the folder and you will see what is in the disk image or you can list the contents in terminal using the ls command