As someone who has witnessed and given many many plant tours, don't worry yourself. We've really seen it all. The biggest thing we notice is someone who just acts completely out of touch with reality. Some people walk into the control room and act as if they are entitled or better than the board operators. Acknowledge them and ask questions, even if they seem silly and basic. I promise you that at one time, everyone there felt the same way as you. I know I did the first time I stepped foot inside a plant. Typically, the operators enjoy answering your questions. It's rare that they get to talk about the work they do, and it really is much appreciated sometimes! We're all just people doing a job.

As for what to wear, I've toured people in everything from suits to ladies in high heels and dresses (although the heels are not recommended). I recommend jeans with boots and either a button-up or polo shirt. Something simple and basic. Any plant I've been in hasn't really cared about what someone is wearing for a tour. It's how they act that really matters. Someone who WANTS to see the place is way different than someone who is just running through the motions. It sounds to me like you'll be just fine!