I'm not trans, I'm bi, but I hope I can still help 😬
I normally don't trust wikiHow but this specific article was really helpful for me and I hope it'd help you: https://www.wikihow.com/Come-Out-to-Your-Parents 😊
There is a lot to consider, like how supportive they are, how old you are, how aware they are about being transgender, etc. 😕
You know your family, so I think you can be the judge of if you need a back up plan. My parents didn't throw me out, but I did still contact my friend just in case. It would break my heart if your family didn't accept you, though 💔
I wish you the best 🏳️🌈
And if I may ask, what are your pronouns?