I’m studying to become a biologist, I think I should understand that. But here, let me explain a small, clearly defined area of biology to you.
There are two chromosomes that determine your gender, X and Y.
If you get two X chromosomes, like me, you are female.
If you get an X and a Y you are male.
And before you say it,
There is also a very rare chance that someone could have an extra X chromosome, which typically does not affect that much.