Yelp...

Depends on who and their beliefs.. if you dont know their beliefs, try talking casually about a favorite thing of yours that has something lgbtq. Their reaction should tell you.
I'm all here for advice :)

Thank you :)

Well, First, You should find out how they feel about lgbt through non-direct questions

Alright

you kinda just did

you first check if they support lgbtq+
then u should slide into it: you can make a joke about lgtbq+ stuff
if you are coming out about gender u can say "i know you have known me as ___ but I feel that I am actually _____ and these pronouns make me happy."
for sexuality you could say: "this could be hard for you but I have to come out to you, otherwise it feels like I am hiding myself from you. i am ____"
good luck!

Thank you!

make a poster of a flag in your room and leave a note that says You're ( Insert Sexuality)