Apple Clothing!

You can get Apple Park t-shirts, totes, and sometime hats at the Apple Park Visitor Center, and Apple t-shirts, pens, water bottles, and notebooks at the Apple Store at Infinite Loop. Right now there is not much of a selection due to supply chain issues. Other than that you can search eBay and find items or know someone working at Apple Education Community that gets extra. I worked at Apple as an AppleCare-At-Home chat advisor and Apple frequently would send out branded items for the department/area you work in.