First of all …. NOT a stupid question whatsoever . . .
All you need to do is create a new menu item in one of your displayed menus – be it your Main Nav Menu or whatever menu you choose – name it “Shop” or whatever you want – and assign that menu item to Virtuemart from the “Type” list.
From that point, it is up to you how deep you want to create your own navigation into your Virtuemart based store – and you simply assign your various menu items (be they general categories or specific items. Either way, you will need to know the link and/or category ID to the particular item (within Virtuemart) to be able to assign it to the menu item.
OR . . . .
There are several navigation extensions available for VirtueMart which can be found within the VirtueMart Extension Directory –> http://extensions.virtuemart.net/
My personal favorite is called “Cherry Picker” –> http://www.galt.md/ …. which is a multi-layer navigation scheme (modeled after Amazon.com’s product navigation, but also similar to Magento’s layered navigation). This extension pretty much does the linking/configuration for you (after you configure your products within the VirtueMart backend, of course). You will also need to do some relatively basic css styling to style the menu to your liking … but this is really not a difficult task (and it’s something you really need to learn and become relatively comfortable with anyway (i.e. css syling))
There are MANY other third-party custom themes and very cool extensions available – many free and/or very reasonably priced . . . so be sure to check them out.
😎