I don't suggest legally changing your name in court until you're OK with everyone in the world knowing about it. There are a lot of things you can do secretly - everything from wardrobe and presentation changes to hormones and surgery - but official name and gender marker changes are super super public. Can't hide them. Don't try. It'll just get you in trouble.
However, you do have, under U.S. federal law, the right to change your name at will by common law. What that means is that you simply start using the name you want to use. In order to use it officially for school, banks, etc, you may need to produce something like a sworn affidavit of name change, depending on the state, but you don't have to go to court and have it recorded. When you do it this way, it's a much slower process with no clear deadlines to notify government agencies, and in theory you can drag out the 'limbo' state where you're still legally using both names pretty much as long as you want. That is, as long as you're OK with your documentation not matching up. (This means that certain HR people where you work will have to know your old name, so that your tax withholding can be filed correctly, and there may be other situations where it'll out you. But it's better than nothing.)
