I work for a company that has no dress code. There is a general guideline: “When in doubt, dress like you’re going to Target”. Glad they didn’t say Wal-Mart! However for interviews they instruct people to show up in business wear. I had to dust off a tie… which now hasn’t been worn since the interview.
There’s a comedian, Dan Mintz (most people know him from Bob’s Burgers), who does a bit about showing up to an interview wearing an astronaut’s suit with helmet, “because they say to dress for the job you WANT”.
I’d probably wear a nice, collared shirt that buttons, with non-jean pants and decent shoes. Good luck!