In all my years of drinking, I've never once thought someone was cool based specifically on what they ordered. And yes, that includes non-alcoholic drinks.
https://www.quora.com/I-dont-drink-alco ... ing-stupid
What makes someone “cool” in the context of drinking? If they own that drink. If they order it and hold it and drink it with confidence and a I-don't-give-a-damn attitude, they're good in my books. The person that does that is solid in my book.
So the guy who walks around with a water and is comfortable with it and owns it is someone I find far cooler than the kid who'll order a Chivas Regal to try look cool but ends up shuddering with every sip.
That said, you “looking stupid,” isn't a function of what you drink, in my opinion. It could be water, ginger ale, cranberry juice, beer, whiskey, Chateau Latour, whatever. The key is that you carry it and order it with confidence. If you hold it or order it like you're shy and timid, you'll “look stupid.”
When you hold it, hold it out in front of you like a normal drink, as if to say, “yeah, this is what I'm drinking, and I don't give a damn.” Don't show it off, don't scream that you've got a non-alcoholic drink, don't even explain why you've got a non-alcoholic drink unless directly asked. Just hold it and go about your business as if it's the most normal thing in the world.
People that “look stupid” (though I wouldn't precisely say “stupid,” myself) are the ones that seem like they're unsure about it or trying to hide it. You'll be teased more often about that, because it looks like they'll get a rise out of you.
Key point is: order what you want, treat it like it's the most normal thing in the world, and carry yourself with confidence. That's the most important thing.