If you're using an Ubuntu laptop or desktop, you can press Ctrl + Alt + T on your keyboard to open a new terminal window. If you're using a remote Ubuntu server, you can connect using SSH to open a new terminal session.
tar -tvfTo list all the files in myfiles.tar.gz, you can run:
$ tar -tvf myfiles.tar.gz
This command is shorthand for:
$ tar -t -v -f myfiles.tar.gz
The -t option tells tar to list the contents.
The -v ("verbose") option tells tar to show file metadata info. If you omit this option, tar will only show the filenames.
And finally, -f myfiles.tar.gz tells tar which file you want to view.