2003 Hyundai Elantra 03 Hyundai Elantra over heats while dr

2003 Hyundai Elantra 140, 00 miles

basically there was coolant in the car.A little low but not anything to cause alarm. We were driving when we noticed the temp guage was extremely high. So we pulled over and put coolant in and tried to drive it again after letting it sit. Got about 2 miles before it started again. We let it sit over night and then brought more coolant to make sure it had enough we even let it run with the radiator cap off to ensure no air was in the system. Closed the hood and test drove it and it was fine for about 5 minutes then slowely started to go past the half way mark on the guage but as soon as we stop the car or it idles it goes back down. Then once we refilled it again a loud fan noise that wasn't on before came on and I'm not sure if just the coolant was to low so the radiator fan wasn't turning on and since we filled it its coming back on.