PHP isn't that hard to learn, provided you know the basics of programming. You don't need any special editors. You can use Notepad, Notepad plus, Dreamweaver, etc.
As far as I know, you can't use the WYSIWYG side of Dreamweaver though, it's all coded by hand.
Creating a search box is done through html form tags like text field or text area, but the searching itself will call the PHP script.