There are absolutely no right or wrong answers here, only how you feel. The fact that you were able to be with your father before he died, surely mattered the most to you both. Funerals are the worst anyway, an intersection of your most raw and intense grief with a celebration of your loved one’s life.
My brother, who is neither sensitive nor a writer, provided a beautiful eulogy for my dad. My sister, who was probably the most effected after caring for him his last year, actually laughed because that’s her odd way of coping. There is no way I could have held it together to speak, let alone said anything fitting and lasting. The poem I published here last week (Freshly Mowed Grass) is actually the first tribute I’ve written for him — and it’s been 13 years. It doesn’t mean I miss him any less, it provides just the briefest snapshot of him as a father and not at all of the man he was, but I will get there. No right or wrong answers.
I don’t claim to know what happens to souls after death, but I do feel them all around me. Whatever you end up writing will be right for you, and your father will appreciate it. Hugs to you as you sort it out.