What people say is “normal” is just because of what most are. Most people are straight (heterosexual) so some people say that is “normal”. More people in the world speak Mandarin Chinese than any other language. Should we then say it is “normal” for people to speak Mandarin Chinese? No! That would be silly. It is also silly to say that gay people are not normal.
If people do not choose to be gay, then they should not be mistreated or made fun of because of who they are. If you or someone you know is gay, it is okay. Some people are gay and some are not. Love yourself and love others.