As far as I can remember, I had no preferences whatsoever.
I actually had some difficulties to understand that other people had preferences, as a kid I thought different sex couples were much more common only because they wanted to have children.
My first crush was at 8, and only retrospectively I realised it was same biological sex, on the moment it had zero importance (it would probably have been different if I had spoken about it, but I didn't).
I never had much problem with it, partially because I was lucky to have a great environment, partially because my preferences were always in the background compared to my gender identity interrogations (I knew what I LIKED very early, but understanding exactly what I WAS took more time).