The student pilot reported having completed one flight around the airport traffic pattern with a flight instructor in preparation for the student pilot’s first solo flight. They then landed near a fixed base operator at the airport, and the flight instructor exited the helicopter. The student pilot took off and practiced hovering, hovering taxi, and flew three airport traffic patterns before returning to the grass area at the airport for additional hover and hover taxi practice. The windshield began to fog during the additional practice, so the student pilot landed the helicopter to turn the blower fan switch on, but did not engage the collective friction or reduce the engine power. The student pilot said he had never used the blower fan switch, and it took a couple of seconds to locate, during which time the helicopter rolled right, and the main rotor blades contacted the ground. The helicopter came to rest on its left side. The blower fan switch is located near the floor between the pilot’s legs. The helicopter was destroyed by its impact with the ground. The student pilot stated there was no mechanical malfunctions/failures of the helicopter.