application for scripting

hi! I'm a high school student and I want to practice scripting at home. The problem is, I don't know how to and what to download so that i can install a Unix OS in my computer so i can try writing a script.. or can anyone recommend and application that i can use to try and run my scripts.. please help me here..

by the way, what we're using at school is UNIX GNU text based os.

thanks thanks

You can use Cygwin or Mingw to practice scripting on windows or you
can install Linux on your machine like Ubuntu.

thanks..