Yes and No. The pages displayed in your browser are made up of XHTML styled by CSS. XHTML is static and easy for WYSIWYG editors such as Dreamweaver in Design View to interpret and display.
However, Zen Cart uses PHP scripts to generate XHTML. Dreamweaver can't interpret this as it doesn't have a PHP engine to drive the scripts, so in Design View it just shows you yellow boxes where the PHP scripts are located (it works the same way with the other scripting languages that it supports).
So to see your site you need a PHP scripting engine. Your remote server will has one, and you can install them on your local PC too (Google XAMPP, WAMP and MAMP), to enable XHTML to be generated and sent to your browser. A very common way of working is to have two windows open, a text editor (such as Dreamweaver Code View) and a browser window. You make changes in your editor, upload them and refresh your browser window. With Dreamweaver this can be exceptionally quick. Just set your preferences so that clicking the upload button does an auto save. Then each time you make a change, click upload then refresh in your browser to see instantly the impact of your changes.
That browser is usually Firefox. Firefox has some very neat extensions for helping developers. The web developer toolbar has long been popular, but for many is being superceded by the Firebug extension (though both have unique facilities). Amongst other things, Firebug allows you to click on an object in your browser and see what XHTML generates it and what CSS styles are attached to it. You can even experiment with editing them there to see what effect the changes will have, before returning to your text editor window to commit the ones that work for you.
However, you may still choose to use a WYSIWYG editor to create chunks of HTML that you can cut and paste into Zen Cart. Your define pages (such as the block that appears at the top of your center column on your home page), your EZ-Pages and HTML banners, can all be created this way.