How do you uhh emotion

I’m SO bad at expressing myself. I’m also terrible at like… well, my dad called it “empathizing”. I thought I knew what that was, but now I’m kinda confused. People always seem kinda disappointed when I try to acknowledge their heavy feelings. I’m so bad actually that my family has started politely encouraging me to stay home from funerals

But frrrr I never know how to act to show them I understand they feel bad?? I also have a bad habit of smiling in any tense situation, which isn’t very good when I’m getting punished…

My sister’s started thinking I’m a sociopath atp and I dunno what to do about it. I feel like this is a dumb and broad question, and this is the worst place to ask it, but how do you express “empathy” instead of “sympathy”? Because I keep doing things and people keep getting concerned and I don’t want them to be ;^^