DVD Hook up-Olevia 266-T11

Question

I am a novice when It comes to anything electrical, But I want to simply hook up my DVD player to my TV. I bought the converter box because the Olevia doesn't have a video in slot. Now I have a standard cable hooked up to the box that the DVD player is hooked into. Everything is in place, but why can't I see the DVD screen. I checked every source, and I had this TV and DVD player hooked up before I moved so I know it works. I just forgot how.