Comments on the begining ok, offers to read when done better.

Emrys stood in line, waiting to buy a turkey leg. He still wasn’t sure why he’d come to this festival. He knew it was likely going to frustrate and annoy him. He’d been drawn here for two reasons, he supposed.
One was to see how people in this world, which had moved on and collectively chosen to forget about its magic, would try to depict a past time when it was still remembered.
Two, the idea of he, a wizard, walking through such a world undisguised (well, except for his clawed hand and foot, but that was a little different) staff in hand, without drawing anyone’s attention appealed to his sense of irony.
So he stood, with a man dressed as a troll (although most of the trolls he’d seen—and he’d seen quite a few—were much less

New version

Emrys stood in line, waiting to buy a turkey leg, with a man dressed as a troll (although most of the trolls he’d seen—and he’d seen quite a few—were less hairy) in front of him and a young lady in short-shorts and a tank top behind him.
He wasn’t sure what had drawn him to this place, a world that had all but forgotten it’s magic. Or why he’d come to the festival—this worlds attempt to re-create a time before the magic was forgotten.
He wanted to see how they’d do it he supposed. And the idea of he, a wizard, walking through such a world undisguised (well, save for his clawed arm and leg, but that was another story) without drawing attention appealed to his sense of irony.
The troll received his turkey leg and Emrys stepped up and

Third version

Emrys stood in line, waiting to buy a turkey leg. In front of him stood a man dressed as a troll. Although, all the trolls Emrys had seen—and he’d seen quite a few—were much less hairy. Behind him was a young woman in short-shorts.
He wasn’t sure what had drawn him to this place, a world that had all but forgotten its magic. Or why he’d come to the festival—this world’s attempt to re-create a time before the magic was rejected.
He supposed he wanted to see how they’d do it. And the idea of him, a wizard, walking through such a world undisguised (well, save for his taloned arm and leg) without drawing attention appealed to his sense of irony.
The troll received his turkey leg and Emrys stepped up and

I think having him list the reasons as he does here sounds a bit stilted, I prefer openings which are more flowing and pull you into the story so you've read a couple of pages even before you stop to think about it.

The main hook you have here is this wizard in a foreign place alien to him; I think you need to play on that more--show all these different sites and sounds which are new to him rather than a queue and just a couple of faceless people either side of him. Showing us a different world through the eyes of a wizard would probably be enough to make me read on, at the moment, if I saw this in a mag I think I would probably skip it.

If you want a running narrative inside his head, might I suggest presenting the narrator mulling over what is at stake here? Whatever the reason he is there for, I'm sure there are some things that are dangerous/antagonistic. Have him mull over the problems he is facing and how he is going to solve them. At the same time, don't be too specific, just enough to get the reader hooked.

You use forgotten two times really close together and that bugged me. Maybe change forgotten to lost in the line "...re-create a time before the magic was forgotten."

Another place I was stopped was in the line "...walking through such a world undisguised (well, save for his clawed arm and leg, but that was another story) without drawing attention appealed to his sense of irony." The portion in parentheses was too long and I felt that it lost continuity. I would cut "but that was another story".

but that was another story

...but it really doesn't take anything away from the opening.