You've got an extremely old television there.
The converter box should have two coax connectors, (the round metal sort), which are in, and out, along with a set of RCA jack outs.
It should look like this in back. Connect the antenna to RF in, connect the TV to RF out. Turn the TV to channel 3, and leave it like that forever.
If the converter does not have a coax out, you'll need to get a different converter box.
As for your DVD player, to connect it to a TV that old, you will need an "RF modulator"...good luck finding one, most companies stopped making them. It turns composite video into a coax signal. Be warned that you're going to get a very, very poor picture and low sound quality from the DVD player doing that, as well.