Toilet bowl water level

How can I adjust the water in the bowl. I have "dry bowl" and smells..

http://www.terrylove.com/wc/toto/mercer_inside_tank.jpg

There is a small refill tube that comes off from rhe ballcock or fill valve inside the toilet tank. There has to be a stream of water that comes out of that tube. And that stream of water has to be directed to the tank overflow. The overflow may be a tube standing near the flapper or it may be a part of the tank casting.
Look and see.......

http://www.terrylove.com/wc/briggs/briggs_1.jpg
If the fill tube is in place, then the other determining factor is the height of the bend of the trapway.
The top of the bend, is like a "dam" holding water in the bowl.
The water will not go higher than the dam.

The water level in the BOWL is not adjustable. Possibly you are getting no refill from the tank; also possible is a bad vent causing siphomn action, or a crack in the throat of the toilet/

booster....what is a water spot?

The surface area, and Terry whose toilet is that a cutaway of? It comes awfully close to being double trapped.

That's a Briggs Vacuity.

Though it's becoming a trend for leaving some water in the lower trapway to create more siphon.