One of the first to add my new Facebook profile was a Catholic priest. I wasn't really that surprised, but it's worth mentioning. I also received a very supportive message from another priest, and some other priests sent me neutral but friendly messages. I know through third parties that others have been less positive, but at least they chose not to say anything to me. In general, I have been positively surprised with how friendly people (both lay and cleric) in the Church have been.
One of my aunts, who I believed would need a few months to come around (if she ever would), sent me a very nice text message admitting this was "unfamiliar", but clearly expressing her intention to be accepting and to do her best with name and pronouns. We have also been more in contact (no big conversations or things like that, but small things like commenting more on social networks and so on) since then, than we had been in a long time.
Classmates from high school, who I barely knew even then, contacted me to express their support. As did my former boss - who I haven't spoken to since I disappeared out of the blue because of depression.
Oh, and lastly: Another aunt of mine decided to tell my first homeroom teacher (they're friends, and she still gives her updates about me) by saying "I have lost a nephew, but got another niece". Instead of connecting the dots, she feared that something bad had happened to me, and when my aunt explained that no, no need to worry, that I was perfectly well, but that I was transitioning, she started laughing and said "Oh, it's only that!". At least she had no problems processing the news. And my aunt learned that she should use a less dramatic line next time.