When I turn the knob tgo "cold water," no water will not run into the washer. However when I turn the knob to "hot water," hot water runs into the washer, and it washes perfectly. What is the problem, and how do I fix it?

You could have a bad cold water valve, dirt in the cold water screen, a bad cold water solenoid, a crimped cold water hose etc. Pull the washer away from the wall, turn off the water at the wall box, disconnect the CW line at the washer and put the end in a bucket. SLOWLY turn on the CW. What happens? If no CW, the problem is in the supply side, a plugged or bad water valve. If CW, the problem is in the washer. Now look into the fitting for the CW.. Is the screen clean? If so, you possibly have a bad solenoid valve or a broken wire or a bad selector switch. You'll need to do a little inspection work to find the problem by a process of elimination.