How do you maintain a “man-to-woman frame” when you struggle being sexual?

I’m in college and I haven’t realized until now how poorly I do with sexual conversations. It’s not like it pops up very often, but when it does, such as a friend making me pretend to be my other friend’s boyfriend, I just get awkward. I don’t wanna be that dude. I can come up with a smooth response... after the fact. I also don’t initiate sexual conversations, I’m just unsure how to do it without being awkward. I want to be someone who can maintain a man to woman frame, not remain a boy. It’s not like girls will come up to me so they could lead sexual dynamics, I want to do it myself.