"I like this blue dress."
Translation:Eu gosto deste vestido azul.
There is a grammatical difference, "deste" is near you and "desse" it's far, but we don't use this when talking, actually we use it wrongly. But when you reading a book or texting (it's written), for example, we use it. (and we don't usually use "deste" when we're talking, when we want to mean it's far we use "lá")
Welcome! And yes, it's a good way to think, but remember we don't pay attention to this when chatting. Let's pretend the dress is in the left of a storefront, you could say "Eu gosto do vestido azul de lá" or "Eu gosto daquele vestido azul". Obviously, it depends of the context, but both could be used to refer a dress you saw in another story too. When we speak we don't pay attention to "deste/desse/esse/este" because we can use hands and head to show exactly which dress we're talking about. We add "de" because it's from there, but you can also use "que está" (which is), if you use the second way it seems to be the dress in the store you are.
-I'm not born to teach D: Hope it helps. Anything you can ask me again.