First attempt was memorably bad, and indirectly led to the end of a 2-year relationship. You tend not to forget something like that, and in my case I sort of obsessively over-analyzed it for years after the fact, trying to figure out what I needed to do to prevent something similar from happening in future relationships.

First real-actual time was with a different (and more experienced) partner who was just as pent-up as I was. Again, the circumstances surrounding it were weird enough that a lot of the details are lodged in my brain to this day, but overall, it was a positive experience in spite of the punctured waterbed, the rickety cot walking its way across the cold concrete floor of the basement, and my mother almost walking in on us when she came home while we were in the shower together. Honestly, though? It's still something I try not to think about, because all of that happened with someone who just ended up using and manipulating me later on.

So to answer your question, I guess it's possible to have a positive and even momentous first time, but still associate it with a great deal of shame and emotional trauma.