I like this girl in my class (kinda sorta)

For background, I’m a sophomore in high school. I’m fifteen, I’m trans (ftm) and I’m not out to most people in my grade. I’m pretty sure this girl knows but I’ve never outright told her (mutual friends refer to me by chosen name, pronouns, whatnot.)

So she’s bisexual with a preference to women. I know for a fact I’m not her type— I’m kind of chopped and I’m a little obnoxious— but she’s dated worse so I’m not worried. Anywho, recently (about a week ago) she broke up with a guy she had been dating for about a month because he was going to juvie for assault. Before this, she dated a girl for about 5~ months.

Today we went to see the Billie Eilish tour movie. I’m not a huge fan of Billie but went anyways because it was for her birthday. On the drive home, I told one of my friends (who immediately let it slip to everyone else in the car, but luckily the girl in question had left already.)

I’m not sure what to do. I’m not head over heels, but she’s really pretty and nice and I’ve got some serious interest in her. How and when should I go about asking her out?