Context: I'm almost 18, MtF, pre-everything, kind of out

1. My Mom Doesn't Use my Pronouns What do I do?

My mom was the first person I told when I realized what I was feeling, and she seems very supportive overall, she just always refers to me using masculine words. I'm too afraid to correct her, what should I do?

2. Names?

I've already decided that I'd like to change my middle name to my mother's first name, since my current middle name is my farher's, the problem is my first name. My first name is technically gender neutral, but it's generally associated with men. So how should I choose a new name, should I even bother?

3. Clothing?

Simple, how do I find clothes that fit? Is there a direct size translation? (Why do we even have separate clothing measurements?)

4. Locker/Rest Rooms?

Where do I go? I'm comfortable enough going to the men's room but I know it might get a bit uncomfortable if and when I start physically transitioning. I'm afraid to go into women's locker rooms because I still look like a dude and gender neutral rest/locker rooms either don't exist or are so far out of the way that I may as well just keep using the men's room. What makes this more infuriating is that this trans guy at my school uses the men's room and no one says anything and, with no intention of disrespect, he still looks like a girl. I'm pretty sure if I were to do the opposite, well, I'd rather not think about it.

5. Hair

My head is already losing hair and the rest of my body looks like a bear (gee, thanks Dad). As far as my body, I've been trying to shave more often, but it seems to come back quicker each time, so I don't think that's a sustainable solution. As far as my head I don't have any solution, so I really need advice on that.

6. Am I Still Allowed to Like Girls?

I'm omnisexual and I know lesbians are a thing, but I'm worried that people will think, "He's obviously pretending to be a girl so he can get with people who don't want him." That's not the case at all, but I always worry that people might think that. So, am I still allowed to like girls, if so, how do I stop worrying about the thought that people might think I'm trying to abuse my identity, in fact...

7. How do I Get Over the Fear That People Will Think I'm Abusing My Identity?

I guess this ties back into the locker/rest room thing and the liking girls thing. The main thing holding me back is the fear that people will think that I'm calling myself a girl to do something bad. I know that it isn't true, but, even outside of the whole trans thing, I care a lot (probably too much) about how others perceive me. So how do I break away from that mindset?

Thank you for your time and hopefully some of you can answer my questions.