Remove rad cap
Loosen and pull off either heater hose at the fire wall
If there is a Valve on the heater hose push it open(move it) with your finger, it is vacuum operated you can't hurt it.
That should let any air out
Put heater hose back on
Top up Rad
Gurgling sound usually means hot spots from air OR lack of cooling.
When engine is shut off coolant stops flowing, no water pump, so if there was any air or hot spots the coolant in that spot will flash to steam, making that gurgling noise
Leave rad cap off and start COLD ENGINE, no coolant should be pushed out, if so you may have a cracked head or blown head gasket, more on that later
let engine run a bit and and top it up, put cap back on
Getting hot at idle when stopped is classic sign of failed Fan clutch, after engine is warmed up, 10-20 min drive, shut off engine and pop the hood
Try to spin the fan, it should NOT spin, you should be able to move it but it will be stiff, hard to move, if not then replace fan clutch
head/gasket issue
get a latex glove or balloon
Remove rad cap, COLD engine
Remove Overflow hose from rad cap opening, plug this opening with vacuum cap, or gum or putty or ????
Put latex glove over rad cap opening and seal it with a rubber band, or put balloon over rad cap opening
Disable SPARK, unplug coil pack(s), you want a No Start
Crank engine over and WATCH the Glove
If it bounces then you do have a cracked head or head gasket issue
If it just lays there then you do NOT