Hi.
Dreamweaver is only an editor and you should really avoid relying on using tools specific to any editor. At least until you can use PHP without those tools.
I'm not sure there are any PHP specific tools in Dreamweaver tho, come to think about it.
To learn PHP, I would recommend reading some of the online tutorials. They can tell you all you need to know about the basics. W3Schools is very good.
You can also try a Google search for PHP tutorial. That should give you a few good links.
You should also pay a visit to
php.net, the official PHP web, where you can find a list of all PHP functions and classes, which are usually accompanied with examples of their usage.
All PHP developers should have a bookmark or two to this web.