What can I do at my great grandmothers funeral?

So my great grandmother just died. And I want to do something special at the funeral. But I am only an early teen. I thought I could do a photo board for the reception but they don't want one. and i can't sing either so that isn't an option. any ideas? all are appreciated. Also, This is the first family funeral I have ever had to attend. What is the proper behavior for a family funeral? also, what kind of clothes should I ware.? I know I should wear a dress But I dint know how fancy or anything. al hep is appreciated :)