Accidentally I reset my network, and now I can't connect to internet via wi-fi. with error message " There was a problem communicating with the web proxy server (HTTP)

I bought this Ipad2 with the help of my friends and it happened to be actually the second hand. I found out that it has this cynthia icon, i tried to get to get rid of it, but I don't know how. i want to upgrade and accidentally i reset my network, and now, I can't connect to internet via wi-fi (since my sim card broken), the message appeared "there was a problem communicating with the web proxy server (HTTP). now my version is 5.1.1 (9B206). please help me out