Long hair ugh
Long hair is something that I struggle with myself sometimes I'm like ye I'm a ducking boy with long hair, and others I'm like duck I look like a girl and go into a corner to cry. It is a pain not being out but if you have seen my reddit you will know that my parents aren't the best with this LGBTQIA stuff and so here are ways to deal with it. :)

I hide my hair by tucking it into a jumper or putting it up in a bun or ponytail, this makes it hidden at the front and makes me feel a lot better. Some other ways that I do in my room is tuck it into my hat and pretend I have short hair, although it may seem stupid it helps with dysphoria a lot and may help you too, although I have never gone out with it you might be able to. Another way or the braver people out there, cut it what are you parents going to do stick it back on. ONLY DO THIS IF IT SAFE FOR YOUR PHYSICAL AND MENTAL HEALTH. If you are worried in anyway shape or form don't cut it.
Remember men also have long hair even trans men, if someone mis genders you before you start transitioning you can still correct them, only do this if you feel OK with people knowing. The way I stopped most dysphoria from my hair is to get people you know well and trust to call you he/him and by your name, I found getting called by my dead name caused a lot more dysphoria from my hair because it made me think that is what was making me get called dead name. make sure that you trust the person first before telling them, if possible get their opinions on trans people out of them before coming out.
Try to stay positive no matter what. I find watch or reading other people's stories help because mostly the stories are about how they got through it and what happened. This will make you feel at home and know that if they got through it so can you. You can go to my STORIES page to help you.