I don't really identify as a girl, but I don't identify as a boy either...what other genders are there?

Depending on your culture and where you live, the possibilities are nearly endless. The reality is that many people find themselves somewhere on a spectrum. Think of a rainbow: if boys are the Red in a rainbow and girls are at the other end as the Blue or Violet, there are many possible colors in between! To list a few: androgyny, bigender, agender. But some people never find a label that they feel perfectly suits them, and that is fine too! It just means you are extra special, and are an extra color of the rainbow that there is not nearly enough of in this world!

this is very natural and common. Gender neutrality corresponds to a neutral gender identity or expression referred to as Neutrois

You don't need to identify as either a man or a woman. There is such a thing as "gender fluid." Which is: having an overlap of, or indefinite lines between, gender identity; having two or more genders (being bigender, trigender, or pangender); having no gender (being agender, nongendered, genderless, genderfree or neutrois); moving between genders or having a fluctuating gender identity (genderfluid)

I am genderfluid. That means some days I identify as male, others as female. Another choice would be to identify as agender, or without any gender identity.

There are many different genders, and just because you don't identify as a boy or a girl does not mean you don't have a gender. You could be non-binary, and there are many more.

Agender, neutrois, bigender, non-binary, magiboy/magigirl. There's a lot of words out there and they all mean slightly different things. I recommend just looking under the "non-binary" category and finding which best suits your case.

There are many other genders as far as the LGBT+ community goes, however the most common ones other than identifying as male or female, is genderfluid or agender. There are also other genders such as bigender, trigender, and many more :)

If you don't identify 100% as either a boy or a girl, your identity lies in the non-binary spectrum. Non-binary people do not identify as entirely male or female. It's a large spectrum, every non-binary person has a different identity with different and sometimes variable degrees of masculinity and femininity. There are also agender people, who don't identify with any gender at all, to any degree. Only you can understand what definition describes you better, but I also suggest to get in the contact with the non-binary community, that can be extremely helpful in helping you understand the reality of non-binarism and figuring out if it sounds like you.

Opposite to what you've might have learnt, gender is very fluid. There are many types of genders you could identify as, such as genderfluid or intersex. If you're looking for the specifications of each tag, google is your best friend!

Genderqueer is an all-inclusive term for genders that fall outside the traditional binary genders of male and female. I would say google 'genderqueer' to find out more about the different genders. Wikipedia may be of some use, as they have an article on genderqueer.