You're entitled to mess up. Everyone does. Everyone is ignorant no matter if they think they know everything.
Its ok to ask questions. But if you were intentonally being disrespectful like some ppl, then she has a right to not fukk with you.
If you dont like Trans ppl and aren't forced in a workplace setting or school to be around them, dont stress yourself out by being around them if you dont care to learn about it.
We are in a different time. Even though Trans ppl existed even back in the day and were stealth (living as Cis/regular ppl). Trans stuff is visible now. Ppl have lgbtqia siblings, kids, cousins, best friends who they've dealt with for years intimately and acknowledge their dysphoria, discrimination, bullying and how serious it is for them. You misgendering the friend couldve ruined the person's entire day. Or worse. You couldve triggered them to suicide....you may think its weak minded but regular cis folks are haunted with severe depression in the same ways.
Trans ppl (particularly Trans women) regularly get spit on in public spaces, punched on by men and women, made fun of in front of everyone, stabbed...just a lot of violence while trying to avoid major drama. Just going about their day.
If the person is dressed femininely and you know they are supposedly Trans, its likely someone who identifies as a chick. If you see breasts too...another sign.
Its best to just address ppl by name.