There are a number of resources available on our site to help you get started with dynamic web development.
There is the "Web Development: Before you begin" tutorial in the General TechNotes section of any of the product support pages such as the DataAssist support page:
This will walk you through setting up a web server on your computer and configuring the PHP processor so you can serve PHP pages.
In the Training section, there are the Dreamweaver Simulations, the "Setting up your site for dynamic development " simulation will help you with configuring your Dreamweaver site:
If you still find you self struggling, please provide some details on what is going wrong. Are you getting error messages when trying to preview in the browser? a white screen?
Be as detailed as possible, it will help us understand the nature of the problem so we can give better advice.
You really should start a new thread for this rather than tack on to exiting discussion.