So sorry to hear about your Grandpa, Stephie. Times like these are so HARD and SO STRESSFUL. You are perfectly normal for being scared and leary and not knowing what to say to people at a time like this. Just be who you are and don't worry about it. Your Grandma knows what you don't say. Just your presence is enough. She can see on your face what you're thinking and that is comfort enough; she'll know how much you loved your Grandpa. Just give her hugs, you don't even have to say anything.
I know how you feel about not wanting to look. When my Grandma died 34 years ago, I was 17. I couldn't even go to her funeral. I couldn't handle it. I have never regretted not going. I just wanted you to know that you're not weird for not wanting to see your grandpa like that. Big hugs to you sweetie, Terri