Due to the high amount of ignorance and violence transgender people face in our society, I decided to write something explaining how we feel towards stuff. Let's start with some basic definitions:

-Sex: A series of physical characteristics that get assigned a gender by society.

-Gender: The definition of gender is unclear, but it refers to how a person feels relating to their identity.

-Cisgender: The mayority of the population, those that feel comfortable with the gender they got assigned at birth.

-Transgender: Those who aren't comfortable with the gender they got assigned at birth and prefer to live according to their true, not assigned gender (binary or not).

-Binary genders: Male and female.

-Non-binary gender identities: Those gender identities who are neither male or female. They are located in a spectrum, and can be an intermediate gender between the two binaries or something completely different.

-Agender: A nonbinary identity which consists on not conforming to any gender.

-Bigender: A nonbinary identity which consists on conforming to two genders at the same time.

-Gender dysphoria: A physical or phychological pain a transgender person feels for not living according to their two gender. Can be experienced form physical characteristics as well as socially living as another gender. Hormone levels also affect dysphoria, thus transgender people often fall into depression at the start of puberty. 

-Intersex: Someone whose genitals at birth are neither a penis or a vagina, so they sadly typically get surgery to assign them one of the binary genders. If they feel neither male nor female, they can choose to identify as intergender.

Transgender people often face violence from society in different ways when they try to live their lifes as their true gender, mostly when society wants them to live as another gender. Trans people can get kicked out of their homes by unaccepting parents, harrased, abused, or even being assasinated for trying to live their life the way they want. Trans women also get transmisogyny directed as them, because our sole existance is an attack to the patriarchal institutions. By wanting to live as women while being assigned by society the male gender, we are attacking the principle that, under patriarchy, the male gender is seen as dominant or stronger over the female gender.

Also, many people do not get that there are more than two genders, which historically have existed throughout different cultures, such as the Native American "Two spirit". This causes violence towards nonbinary people, as their genders get erased. 

But really, all transgender identities get their share of violence on the basis that  gender is inmutable under patriarchy.

There also exist "TERFS" or "transgender exclusionary radical feminists", who try to be feminists but at the same time are transphobic. In reality, since feminism promotes gender equality between and people, TERFS aren't really feminists since they don't want this same treatement to transgender people.

Really, if you with to be an useful ally you have to be careful with what you say, as if you are misinformed you could cause more harm than good. Lurking transgender spaces online can get you an idea on what's ok and what's not.