Hi Kayden,
Welcome! I joined this site a couple years ago and it's been really helpful for me. Don't be afraid to search around and look for conversations to read and jump in and ask questions.
As to you first question about how to know if you're trans this is a difficult one, and really is only one that you yourself can answer. In my particular case I knew that from a young age I really didn't want to be a boy - and that feeling is with me to this very day. For me, I came to the point where I realized I needed to explore this more because I was very unhappy. I am happier now that I have been figuring myself out and learning who I am. As it turns out, it feels much more normal for me to be a girl.
But there are lots of experiences of people from all over the world who post here. Each of our experiences and feelings are a bit different, so don't let anyone tell you who or what you are; only you're the one who ultimately can discover and decide your life path and answer the question you asked.
I'm sorry there's no simple test or answer. I guess the most simple answer is that you are trans if you say you are.
Welcome! You've discovered a great place with lots of helpful people and information. Don't be a stranger
