It depends surely on the context. San Franciso’s tertiary hospitals would have a different outlook to some theocracy somewhere (or other parts of the USA too) and I don’t know where you are. In my specialty there are LGBT men and women everywhere. One of my closest colleagues is an openly gay dad who just took parental leave for his newborn and is completely supported. In my private practice of a dozen docs anyone who harassed another on the basis of sexual orientation would be expelled without further discussion (along with other harassment it’s in our T&Cs). Some specialties like ortho surgery are more stereotypically straight male but less and less so.

Basically you might face prejudice but it’s completely manageable in most Western big cities, go for it and make the world a better place.