DIAGNOSIS The gurgling is normal refrigerant flow. The buzzing is likely the compressor vibrating against the cabinet or something touching the back.
FIX For buzzing: Unplug the fridge. Gently pull it away from the wall. Check if the metal panel on the back is vibrating against the wall or if the unit is sitting unevenly. Adjust the leveling feet so the fridge is stable and not touching anything. Tighten any visibly loose screws on the back panel.
IF THAT DIDN'T WORK The noise might be items inside rattling against the walls. Rearrange contents so nothing is touching the interior liner, especially near the back where the cooling panel is.
HEADS UP Intermittent gurgling and a slight hum are completely normal operating sounds. The loud buzzing only becomes a problem if it's constant or accompanied by the fridge not cooling.