I really can't remember anything that I would consider my first time making it because as early as I can remember, my mother had me helping in the kitchen and I learned to cook from her.
My most significant first was the first time that I ever cooked in a restaurant. In the early seventies, I lived next door to a little greasy spoon that's seated about 35. They also did catering and as a customer with time on her hands, I used to help them out when they were particularly busy setting up for some party. The owner finally convinced me to come to work for him and I started on graveyard shift, 10:00 to 6:00. I started at 10:00 and the woman that was supposed to work with me that night decided to leave at 10:30. I didn't know the menu, and I had never cooked in a restaurant before. Oh, and did I mention that I was also to be waitress, cook, and dishwasher? I was the only one in the place. I just told everyone that if they told me what it was I was willing to cook it if they were willing to try and eat it. I made it through that night and I worked there for another 2 years. The woman that left me stranded got fired the next day.
I learned a lot in that little greasy spoon and the biggest lesson was what you can do if you have to. It gave me the confidence to go on up from there.