I always had this great idea, but now I want to share it with everyone. With people's help I want to start writing the script for Godfather 4. I already started and It will follow Vincent. This is what came up with, but need help for ideas and mistakes.

“Things could of gone different, but this is how life turned out for me and I have no room in complaining. Who would of thought that I will be sitting on a plane back to Sicily, the murderous land. That land broke my heart and killed my friends and family. I will soon arrive to my Uncle Mike’s funeral, who died just couple of hours ago” Vincent Corleone was thinking.
The plane made was just of Palermo and the airstrip started to be visible to everyone. Vincent learned many things from Uncle Mike, and what that knowledge controlled the Corleone empire and have taken it higher than ever. The Corleone family was the strongest and the most powerful in United States, Cuba, Mexico, and Italy. But Vincent knew with the dead of Michael, a war will erupt in the families and many will reunite to crash the Corleones. Vincent was prepared for this and he had his capos target any many that will be a threat. His thoughts we disturbed by the plane coming down on the airstrip.
A car was waiting for him, Uncle Mike will be buried in the same house he died and also his first wife Apollonia. After the dead of Mary, Michael returned to Long Beach, where he repurchased the mall that was once owned by his father Vito Corleone. The last five years of his life, he returned to Sicily with Kay, who forgave him. Kay has died last year by a heart stroke, Uncle was left alone but wished to stay in Sicily.

How is it that your character is riding a plane to a funeral for someone who died just a couple of hours ago?

Why would there be a war between the families just because Michael died?

He wanted to get there early to get a good seat.

What happened to Douglas?

I take it your native language is not english.

Yeah, that's really become a tired cliché: "Godfather dead. Mob was feared."

It's kinda boring, too.

Vincent tilted his first class seat back and ordered a drink.
Seated next to him was a man who looked familiar, but who he could not exactly place. Finally, curiosity got the better of him and he said, "You look familiar to me, but I cannot exactly place you."

"I am," the man said, the musical diector of the Metropolitan Opera of New York.

"Of course," Vincent said, "and I'm....."
"Vicent Corleone....mi dispiasce la noticia di Don Michaele."
"Grazie."
Not one to mince words, Vincent immediately began talking about his cousin Anthony, who was still doing operas in Europe, but had never played at the Met.
"It would do my late uncle a great service if you could grant one small favor."
"What is that?"
"Give VIncent the lead tenor role in La Traviata."
"That I cannot do, and I'll tel you why."

He was becoming agitated. "Anthony Corleone ruined one of the MEt's grratest protogees' a natural tenor. We had him taking singing lessons, acting lessons, and along comes Anthony with his guinea charm and olive oil voice and they run off like the two finnocchios they are. And just to show you its not all dollars and cents, let me tell you this...he was young, he was beautiful, he was the best piece of stuff I ever had and I've had 'em all over the world." So you tell that Dago goombah I'm gonna run him out of the business. Now you get outta here and go ride in coach!

^^^ Now that was clever. Me likey.

For the original poster: if Michael was all alone in Sicily, who exactly would be at the house for his bedside Mass? Just random people coming to pay their respects?

Just the dog, and a few of DonTomassino's old servants...maybe Connie?

It is but I not amazing at writing so here I'am trying to get help.

I have the plot for the first part, but will be pleased if someone can help me out with the writing.

Thats a bit harsh.