Point the first: The Zelda games have been around a good twenty years. (Or is it twenty-one now?) They're also one of Nintendo's biggest franchises. Your character might not have played the game, but if they've heard the words "Zelda" and "Triforce" together, they may piece together just who Link is after talking to him. That's gonna be up to you guys to decide for all your characters! But it's something to throw out there, and I thought it might be helpful info for people whose canons might take place in the late eighties/early nineties.
Point the second: If your character would recognize Link, go for it, but please read the rest of this paragraph first. XDb If you know his name, he's going to be very perplexed. If you tell him he's from a video game, he's going to have no idea what you're talking about. I would prefer that people don't really mention his whole time traveling shenanigans at first, no "SUP THREE DAYS," and the same applies to who Sheik really is. This is, of course, liable to change depending on specific situations and character interactions, if Link notices that a character knows more than they let on he might ask them about what they know, etc. But I'd just like for people, audience and characters both, to not just blurt out the bigger spoilers/secrets of the game(s). Very few characters in the Zelda games know the truth about what Link did, so he's gonna be very very shocked to find people here knowing those details.
Bottom line on point the second is feel free to recognize him, but just know he's going to ask who the hell you are and how you know what you know. And please don't blab things like "Link has the Triforce of Courage on his hand!" If you're unsure, just hit me on IRC!
Sorry if that was way tl;dr. This is such new territory for me XD bear with me please! And I'm totally willing to work things out. =] Thanks!