The shell is a program that interprets commands. Most of the commands turn out to be requests to load and run a program. There are hundreds of small utility programs available on computers like petra-k. You can create, copy, rename, and edit files, such as your Web pages.
The most common way to "get a shell" on a remote computer is with the old Telnet protocol. Windows-95 comes with an adequate Telnet client. There are many fine freeware and shareware Telnet clients for MacOS, Windows-95/98, Unix, any computer with Internet access. but Telnet exposes your password to snoopers so we don't use it any more.
Unix users should try
ssh pk.greens.org .
MacOS and MS-Windows users should go back to
Get an account
step 3 and get PuTTY or Nifty Telnet SSHr3 or something.
When you first start a shell, it runs whatever start up chores you have specified, and then prints a prompt into your SSH or Telnet connection. You see the prompt in the display area of whatever program you're using to run SSH or Telnet. You can type a command when you see the prompt.
Once your SSH or Telnet is running and you are running a shell, here are some commands you can try:
grep `whoami` /etc/passwd
echo this is a test > testing.html
lynx -source http://pk.greens.org/~`whoami`/testing.html
If you tried all those commands, you have installed a page on the Web server http://pk.greens.org/~$LOGNAME/testing.html where $LOGNAME represents your login name. Try to read it with your Web browser.