2000 hyundia heat

I have a 2000 hyundia elantra gls 2.0liter 4cyl, 66000 miles, car overheats after driving for 5 to 10 minuets but wont overheat at idle, smoke/steam comes inside car from the heater/ac vents, was told it was a blown head gasket I’m thinking more like a bad thermostat or maybe heater core or hoses, any thoughts…