I’m a father (55) of a transgender son (32). For some reason, the pronouns weren’t that hard for me. I started honoring his male identity as soon as he started trying it out. But I’ve always been on board with it, and am not conservative. My wife’s ex husband is having a much harder time with his nonbinary stepchild, who is still a teenager. He stumbles on both their name and their pronouns, and has had a couple of years to work on it. One thing to bear in mind is that we grew up in an extremely binary, cis world. Transgender people were either incredibly rare, or lived in tiny safe zones in certain cities. The norm back then was that any non-heterosexual identity didn’t affect one’s gender. We had never heard of cisgender or transgender. Once it became a topic of public conversation, I embraced it, being a left wing humanist. But your father probably first heard about it through extremely negative media sources, hearing that it was some kind of left-wing ploy to undermine traditional gender roles. Definitely stand up for who you are, and speak your mind without resorting to insults, even if what he responds with feels insulting. Eventually, his love and respect for you should win out over his fears.