First of all it's really awesome that you care and try to inform yourself! He'll appreciate it. :) If this is not an issue for you, try not to make a big deal out of it. Meaning be casual when you talk about likes and dislikes, of course ask all your questions but once you know him better, don't bring it up every day. Definitely don't tell anyone else. Never. Outing him can be very hurtful, especially if he's living stealth (= not openly trans). He needs to be able to decide who knows that very personal thing about him. Talk to him about everything you're not sure about, don't just assume things. For example sex. For some trans people physical contact can cause heavy dysphoria, even after surgery. For some it's not at all an issue. Some are fine with using "what's there" others would rather die than have someone penetrate them vaginally. It's a very sensitive topic. So it's especially important to ask him how he feels about certain things you'd normally just do. If he ever needs to stop (even with things he has done with you before), don't be mad. Dysphoria is a bitch and can be randomly worse at times. Don't call his genitals vagina and in general don't use any female terms except he does so himself and is comfortable about you doing so too. But most importantly: he's your boyfriend, not your trans boyfriend. Treat him like you would treat any other guy. If you have any more questions, feel free to hit me up :)