Disclaimer: I’m not trans myself. My experience/opinion is formed by listening to my trans friends and observing their experience.
Berlin is largely leftist with some anarcho spaces. Trans acceptance is mandated entry requirement. I’m sure some ahole wiggles in occasionally but I’ve seen others get very vocal and kick them out immediately. I would say it’s an accepting place with several social events geared towards the LGBTQ community. A friend of mine is from the US too and she came to Berlin because of the issues she faced in her home country as a (trans) woman. It’s been about a decade since she got here. I can find out about some forums, spaces you can talk / ask questions in. I don’t want to presume the details and speak for the trans community. Shall I look into it and pm you ?