You will do great. Take it one step at a time. Moment to moment if need be. It sounds like were friends for a while. His parents will probably appreciate anything you say/do. And ww is right, take some mementos you have. They might not have seen them.

At my grandfather's funeral people kept telling me how lucky I was to have such a wonderful man as my grandpa. That short phrase made me feel so much better. Other people knew how special he was.

(((((SC))))) I'll be thinking of you.