As a 5 year PHP coder that has yearned for the liberation of a "better" platform such as ASP.NET, I bid thee good luck.
By itself, you have nothing like MasterPages, UserControls, page execution cycles, handlers, etc. PHP is much more like ASP classic in that the script starts at the top and ends at the bottom. Everything in the middle can be anything you like, and if you want the kind of structure that ASP.NET offered you, then you'll have to implement it yourself.
As soon as you figure your way around the basics, get over the massive lack of organization of the standard library, accept that the bolt-on OOP is a bit clunky, learn to accept PHP for the monster that it is, and still at this point actually want to use it for something serious, you should look into a pre-made framework such as Zend or Codeigniter (among others) that try to get most of the plumbing out of your way.