Is it normal to be bi but prefer one gender over the other

I'd say its normal, I think of my self as being bi-sexual but I would definitely say there is a wider spectrum of girls that I find attractive rather than guys. With guys i always find myself picky on which ones to like but regardless the sex is just as good for both.

I'm bi and enjoy sex equally with men and women. However, I have no interest in being with another man romantically.

Maybe, i haven't been with a guy, though i think about it, i don't know or have any gay friends and if i have an encounter i want it to be open and comfortable. i still have sex with my gf three or four times a week.

Totally normal! Sexual orientation is on a spectrum... check out the Kinsey Scale:

https://www.kinseyinstitute.org/research/publications/kinsey-scale.php

sexuality is a v fluid thing. even straight people have preferences. so ya its v normal and dont worry. ur sexuality is up to u to define.