You can only do this if you create a new account. Your characters are a part of your family and this is the original concept of the game. Any new character will start fresh but you will have the same family name / fame and any other family related perks. The story can be restarted from the ground up for each new character. It's possible that there is a misunderstanding on what a new character does / doesn't do so please feel free to respond and what you want to achieve exactly if my answer wasn't enough. :)

If you're looking in deleting your character, you can do that and start over.

Thank you for your reply.
What I'm looking for is to start the story from the ground up for my new character, and I haven't found a way to do it. Your help will be very useful.
THANKS

Whenever you create a new character you will restart the story from the very beginning and whenever you encounter a fork in the story, it will prompt you and let you know which side of the story you have already completed and the number of times you have. All you need to do is create a new character and you will be able to do so. There is no way to start a game and skip the main story and side quests and believe me... After 23, 24 characters~ish I'd be more than happy to have a way to do this LOL

If the story looks different on your new character, perhaps you created your first character before they added the story remake and you just remember it from way back when. They changed the story, lore and intro of the game last year sometime. Perhaps this is what is confusing you?

Thanks for the answer, but when I create a new character, it appears instead of the active main quest, the most advanced character (lvl 47). I thought I had missed something, so I recreated another one to see.... I didn't miss anything, the 3rd appears instead of the active main quest.
I don't want to skip anything as a quest, I would have just liked to be able to start from the very beginning with a new character from the same family, since the same server, same family.