The make and model of the TV helps but without the same for the DVD and "DVD converter" (is that a digital converter box for HDTV?) we can't know what outputs you have.
The TV has 2 HDMI inputs so use those if possible.
The TV has only one component video (3 RCA jacks) audio (2 RCA jacks) input. That would be used as your next choice.
If the converter box has an RF output you have the option of using the antenna input on the TV. Check the converter box manual on how to connect it.
You may need a input selector box to expand the number of inputs.