Dishwasher won't stop filling with hot water
Definitely sounds like the inlet valve is stuck open or otherwise damaged.

It may need to be replaced, depending on exactly what was damaged.

To turn the water off, follow the water line from the dishwasher, there should be a valve where it attaches to the house plumbing, this will stop the water.  Depending on how it is plumbed it may also shutoff water to the kitchen sink as these water lines are often combined.

The inlet valve is usually right next to where the supply water hose connects on the underside of the dishwasher.

A repair technician could repair it, or an online search with your model number will find you replacement parts and instructions on how to replace it yourself.