What channel should TV be on to view DVD?

This depends on the connector, and the manufacturer of the TV. If it's an RF-type connector (check the link for a picture), then you'll use Channel 3 or 4.

If it's an RCA jacks you're connecting to (yellow, white, & red in the pic), then use the INPUT or TV/VIDEO button on your TV remote and look for AUX1 or AUX2, or maybe just INPUT.

If they are jacks that look like RCA jacks but are green, blue, and red, look for COMPONENT or CMP in the listing.