Tears are good, and to be expected following a significant loss in your life.
There is a "grief process" that you will pass through. Most will happen in the next few weeks, but other parts of it may linger over months, an return again at times like a year from now, and at his or your birthdays.
You don't need to decide right now about being at the funeral. It is meant to be a celebration of the person's life, as a living memorial to honor his life, and to honor the people who meant so much to him.
The funerals I have been to are not what I would call "morbid", rather I would say honoring or even celebrating the person's life with others who will also miss them. Whether you are present, is up to you, and up to your family's wishes.
I'm sorry for your loss. The death of a loved one is a very difficult experience. I mean this in a nice way, but log off of here and spend time with other family and loved ones that understand.