How do I actually *be* trans?

I've conversed with close friends about my many currently irrelevant issue and have come to the conclusion that I would be much happier and more confident with myself as a woman. However, physical transitioning is off the table, as two of three guardians i live with are super transphobic and would make my life hell if I came out (i had to post this on a personal alt since my dad can see my main's posts).

My plan currently is to present feminine in online circles that I know well and trust to respect my decision. However, i'm not sure that would actually count as being trans or just role-playing, as the majority of the aforementioned circles are role-playing servers on Discord. I'm also not even sure how I should act as a girl. I was raised with very southern expectations as to how I should act, and I don't know if any of my current habits and mannerisms would even be cross-compatible.