2007 Chevy silverado 6.0 Liter Gauge shows 0 oil pressure and check engine light is on

First check the oil level but you evidently have a serious engine problem. It could be a bad oil pump, clogged oil filter or a bad rod bearing. If you ran it with no oil pressure the engine will probably need a full rebuild.

On the oil pressure, do you hear a knock or ticking from lack of oil, or oil pressure when running?

no knocking or ticking when running. Oil is fine on dipstick. Since the check engine light is on will it come on if the sending unit goes bad or the gauge/stepper motor goes out?

Possible, but on the oil pressure, if you were to take out the oil pressure sending unit and underneath it in the hole there should be a fine screen type basket that needs to be fished out and cleaned. Over time it will get gummed up and not allow the oil sender to read oil pressure properly. Check engine light may have come on due to the gage reading no oil pressure.