I attached hose to bottom of water heater to drain it loosened the top valve and nothing comes out, how do I drain it?

Either the valve is clogged with sediment or the valve is not opening.

You may have to first shut off water to tank, then remove water valve and get a new one or clean out the old one. The sediment may have filled bottom of tank, so you will have to remove the valve and see what can be done to get out enough to get it started. You may have to repeat the procedure to finally get it clean enough. Make sure to open a hot water valve in an upper bathroom if it is two-story.

Which "loosened the top valve " are you talking about? The drain spigot is at the very bottom of the heater

I am talking about another faucet in the house to break the vacuum on tank. If you do not open some hot water faucets it will form a vacuum in the hot water tank which will prevent the water from coming out of the bottom drain. Sometimes you may have to loosen the pop-off valve to break the vacuum.