"and I would like to know the chances, if possible for that Pikachu to be shiny. Or any methods you can use according to the Pikachu one to make it shiny without a hack"
This question is completely different. The linked one asks can starter Pokémon including Pikachu be shiny or not. But this question also asks for the chances and methods for obtaining it. ;)
2nd reason why I said so to PX and Fizz