My power steering pump makes a growling noise even when the car is idle. The noise is louder when I turn the steering wheel. The power steering fluid has gotten low a couple of times and gets foamy.

If gets low definitely a leak foam is pump mixing fluid with air roar is pump cavitation check lines or pump for leak keep fluid at recommended level air bound unit can cause steering difficulty and or failure if need have trained mech look into problem

The air in the system making the fluid foamy is the cause of the noise. Check for leaks in hoses or connections. Could be a bad internal gasket or seal. Fix id need be.

Then drain or empty the fluid from the reserve and refill with fresh fluid, without running the engine, turn the steering wheel to the left then right as far as it will go about 7 times to bleed out any air.

You can try the bleeding even if there is fluid leak. C

Does it make the growling noise when the fluid is at the correct level? If it does, the noise is a warning that your power steering pump needs to be replaced.