Geno's and Pat's I'm pretty sure are like the Philadelphia versions of the Anchor Bar. I had a friend who grew up a few blocks from there tell me more less those places are just tourist traps. But they are the most famous cheese steak shops and across the street from each other.
There's probably better ones I don't know of but remember this place was pretty good
https://www.eatatshanks.com
Also, Reading Terminal Market is good for food in general..... if you're in center city that should be nearer