Tv won't change channel and is stuck on blue screen

[Applesaucetyler]

I have cox cable and I got a new tv today and I pushed a button on the remote that said on off and I thought that was the off button and now it is stuck on a blue screen and says no signal in upper right corner ... Did I mention it won't let me go to cable .... Please someone help me I don't know what to do

 

[hang-the-9]

Button on what remote? The TV or the cable box? You may want to have a friend come over that knows how to hook up TV connections and select sources.