Dress code is no shorts, sandals tshirts, or athletic clothes. (Clean Tennis shoes are fine). Jeans and a collar on your shirt is all you need.

Most people in your class that aren't new hires, will wear jeans and a polo shirt. New hires tend to not know what to do so they pack only slacks and button ups their first time through. AA is the same casual dress. Personally, I only wear jeans in the building. I might tuck in my shirt for a checkride but that is about it. I have never failed anything and nobody I know in the training center cares the least bit to be honest. At least not anymore. Those types are not around anymore. If someone was wearing a tie, I would tell him to relax and take it off. Far more about attitude than what you are wearing.