When I decided to go fulltime I told my closest friends at the time. And living in a very small town, I didn't have to say it to another person, the rest of the people in town that knows me knows me as Sarah. So that went amazing for me.
But all these people are cis, so they can't relate. Several of them got a genuine intrest and ask me alot of questions which I happily answer, but as for someone to talk to about trans things they're not really that good. They have all been amazing, giving me nice compliments how I dress, my legs, one of my favourit comments by a girl was "you look like a Sarah".
I do got people I can talk to about trans things, mainly my ex girlfriend, who is sort of my mentor and idol. I can ask her anything, no matter how intimate and I'll get the answers. I also got my current girlfriend, although she is not quite as informative, she is increadibly supportive and she is someone I can talk with, about my thoughts, fears, etc. And just having someone I can say "I'm scared of the upcoming SRS" is nice. And I don't see myself talking about that level of intimacy with my friends.