"I could introduce you to some heroes if that's what you're curious about! Back in the Boiling Isles, I'm just a human learning my own way to do magic!"

Granted, helping people was a thing that Luz did all the time, even there. and she's very much underselling how much that help had impacted the friends that she had there, to say nothing of Eda and King. Luz feels just as impacted by all of them though, so she's not likely going to liken herself to anything more than a grateful human who got to learn magic and be in a place where she could learn to be herself.

"You were helping me first though! By that logic I'd say that you're also a hero!"