Need help connected RPi to a hidden SSID network

[Espo]

Our school's wifi is very restrictive, so they made another one for robotics. Last year, some people connected to it during school and got less restrictions, and that was not okay with our school. They made the network hidden, and that makes it much harder for me .

I followed everything in this post (http://stackoverflow.com/questions/3...pi-3-raspbian), but when I try to connect it still doesn't show, and when I do ifconfig -a, wlan0 shows up, but no packets have been received, and no packets have successfully been sent.