I don't want to attend my grandmother's funeral
Will something happen if you go to the funeral?
I think I will get mental scars out of it
Attending a funeral can be a sad experience, but many people find it helpful in moving on. Everyone will expect you to be at your grandmother's funeral, and your parents could really use your support while they're grieving.
You're just being close minded about it, I don't even know my grandmother.
I can understand that you didn't know your grandmother but it is good to try and be there for family when they are grieving. It is expected that you will attend the funerals of loved ones. Your family might want you there for support if you can be there for them.