Any advice for How to Write Like One Piece

So, Ive been a really big fan of One Piece ever since I discovered it and for years I have tried and failed to write a novel series that could rival him. But now I have a general idea that uses Vikings and even have some of the arcs down, but I would love any advice I could get.

For context, its basically like One Piece but with Vikings.

Note: please do not steal my idea.