You can use something like Wordpress or Drupal for the CMS route.. barring that figure out what you want your site to do or to be used for.
If you want to pretend to do the 'hosting' you can download XAMPP/WAMP/LAMP/MAMP (depends on your OS), install it, and run a local apache server and play with that.
XAMPP or your OS equivalent is good for a dev environment but if you just want something quick and dirty on windows (on linux its super easy to get lampp up and running so use that) you could install MS WebMatrix to give you both wysiwyg and code editors a file manager, web server, and debuging tools in one installable software package. It should still be free but havent used it in a long time. You dont have to use asp.net or whatever MS stuff either (ick) and can stick with good ol php/sql/js/css/html et al.