What if I can't cry at the funeral?

I think it is normal. I've heard people say you can't cry before, but everyone else is crying. I think there are two possibilities for you to cry. One is that you are too sad to cry to the extreme, and the other is that you are not familiar with the deceased and have no feelings, so it is normal to have no tears. If you can't, show your sadness, and others won't care too much about you.