Hi lexeb. Welcome to the forums.
In my view, you are asking the wrong question. You should be asking—How do HTML, CSS etc. work? They are the important things. Don't get distracted by the tool itself, because it doesn't matter what tool you use to create a website. Ideally, whether you are using Dw or some other tool, use them to write good, clean code—that is, as a code editor. If you use Dw as a WYSIWYG tool (visually dragging and dropping elements etc.) you are guaranteed to produce junky websites. So it's good advice to steer clear of those functions.
Each code editor has a few tricks / tools for writing code, like autocomplete etc., but you quickly learn what they are.