I don't know much English, sorry. Throughout my childhood I have lived a typical heteo life. I liked children, everything "normal". Now at puberty that changed, I started to like the female gender, I still don't know if specifically I stopped liking the boys or that, I never had boyfriends (at this moment I don't even want to), instead girlfriends did. I have no doubt that I like girls. But that yes, there is fear that this will change like several cases in my family. The thing does not end there, too, I am in doubt with my gender. Sometimes I have doubts about being a trans boy, not binary or something like that. I have read about gender dysphoria, and I think I have some things from there, and from what I have read that is not very good, but I am attracted to my image belonging to the opposite gender. Also recently I came out of the closet with my close family (they know that I still don't know what label I have, but they don't know anything about the trans issue), although everything went well, and was a little, depressing? especially because I would like to know who I am and I don't know, and on the side of being trans it is something that I remind myself every day, I can no longer sleep in peace because of this enormous fear and doubts, please help.
My biggest piece of advice for if you're uncertain on whether you're trans or not is this: start "Boy Moding" it out, that is, dress in a style that's more masculine leaning than it is feminine. Present yourself as a boy. If you're small chested enough you could get away with a heavy duty sports bra to flatten out your chest. I know it might not do a lot, but it could help. If you're a bit larger in the chest, a Binder is your friend. Walk in a more masculine way. Pretend as though there is something between your legs that if you walk wrong, you'll pinch. Try lowering the register of your voice. That is, if your voice is more nasal or throaty in where you speak from, try going for the chest or diaphragm. Before the start of my own Transition, I would "Girl Mode" when I went to a local venue. When not at work, but still out, I'd spend less and less time in "Boy Mode". Until eventually I "Girl Moded" it Karaoke, when I had my sudden realisation of who I am. I then gave my old self a final day in the sun of the end of that work week.(Even though I knew beyond a shadow of a doubt at that revelation, I still needed to give myself the time to process)
Puberty is when things started to get problematic for me because things began to change in ways i had been dreading. If you can, try to assess your feelings about gender separately from your sexuality. Regarding your orientation, you are still young, so there is no rush to label yourself. If you are sure that you like girls, and you have no desire to date a boy, there is no pressure to try. There is nothing 'wrong' with what you are feeling, so please don't lose sleep over it. There are lots of people here and resources that can help with more information. And your English is pretty good, don't worry