Potty Training Update

So the first morning of potty training was a complete failure. We had 2 accidents and a meltdown. I feel like a failure. I feel as though the first real challnge that I have faced and I am not succeeding at all! My daughter will be 3 on Monday and she has never gone in the toilet. She will sit on it, but she has never actually gone. My dad said that she is manipulating me and I should still make her sit in there, even after the melt down. I of course, at that point, put her back in a diaper. I know that she is manipulating me and that she knows if she throws a fit, I will give in. But does forcing her make it better or worse.
Help, Please!!