I don't feel empathy for people
What do you feel empathy on if not for people?
I only feel empathy for animals.
Being empathetic towards animals is fine, but that should also extend to people. Your family and friends are people, do you have no empathy for them?
I know that. I still don't feel it on people.
You need to go to a mental health professional if you don't feel any empathy for people, even friends and family. It is hard to build bonds and connections like that.