What is courtship, and what is an appropiate age to start courting?

I've been hearing a lot about courtship lately and I was wondering what exactly it was. This girl that I like is not allowed to date, she's just not. It's a long story so I'm not gonna go into detail at this time. Anyways, I've known her for some time now, and I have never felt this way about someone before, and I told her how I felt and she's like, "awww, that's so sweet, I feel the same way about you." So then we got to talking, and talking, and talking, and then we did a little bit more talking until her daddy walked in one night and kicked her off the phone at 2:30 in the morning, and we found out that we have a lot in common. I feel like if given the chance, I could spend the rest of my life with her. I really like her, in fact I believe I love her. So I was wondering what courting is, and if I am at an appropiate age to ask her father to court her, and if not, what is an appropiate age. I am 16 years old