Design pattern and OOP in PHP?

I've been working with PHP and few more OOP languages and still wondering about the meaning of design pattern and OOP in PHP and similar languages.

I have some modules in my project: news , forum... Each module can be access by calling it main class.

• The main class routes the page ~> point to news/article , news/categories.
• Have some module settings / variables.

And the child classes in each module handle those specific features / pages.

What's the best design pattern for this model? Create instance of the class or it's child?

Now, i initialize a class, and access to the child class static methods like the example bellow. But i've read using static method can slow down the code?

class news {
  __construct() {
     // define module settings
     ...
     // routing all module pages
     categories::list();
  }
  function modulesetting() {}
}
class categories extends news {
  static function list() {}
}