How to Use Voltage Regulator

I bought a box of 78xx voltage linear regulators to step down 5 VDC USB power to 3 VDC to eventually use to power my ESP32 microprocessor I am building a project with. It did not work properly, because I didn't wire it up correctly. Fortunately, I was just testing it, so nothing got fried in the process. But I'm learning.

The Poison Plastic.

"You know PVC and you don't know PVC: "New car smell? New shower curtain smell? That's the smell of poisonous chemicals off-gassing from the PVC."