Honestly if you don't have a HDTV you should go out and buy one....your not getting the real next gen or even last gen experience without one IMO. Im pretty sure the X1 can support SD tv but you will have to buy the cord from a store yourself being that
the X1 only ships with an hdmi cable only.
HDMI cable is a cord that connects your console to the TV thats how your able to see the image on the TV from your console. Unless you have an HDMI output you will have to buy an AV cord from best buy or something.