Dreamweaver isn't going to be the least bit useful for working with PHP and MySQL. At best, you can use it to WYSIWYG build a static HTML framework of what the page will look like, and then salvage the generated HTML and CSS for use in the PHP. If all you're using it for is a code editor, I would suggest that you learn a real flat file editor such as ViM or Notepad++. In the long run you'll be much happier and more productive, and you'll have a much larger choice of schools to choose from.

Try Googling "using dreamweaver with php and mysql". There are plenty of tutorials out there from sites like Adobe, Sitepointe and even Princeton University.