Overheating

So I bought and replace a new radiator yesterday and filled it with water let it run for about ten fifteen minutes. I drove it home, today i started it up then filled the radiator with coolant and let it run until it got warm inside bout ten minutes. Drove it around a little and parked it. Maybe an hour later I go to take it for a drive and it starts over heating I think when I had it on in park. But then the heater stopped working and when I began to drive the gage was going up then down then just continued to raise so I had to drive a little and stop til I got home which was only a few miles. But it was steaming real bad only coming from the little hose that goes into the little coolant tank the overflow I think it's called.