Preparing early

Hi I’m a highschool senior and due to me only caring around late sophomore year my gpa would be too low to make it to a target school and I’m worried because I want to go into finance and feel I would be at a disadvantage without a MBA from a top institution.With that said how do I make a application that people will jump at I’m sure I can get a good GPA and I need to know if I should be joining finance clubs left and right and if I should buy a GRE book.i really am passionate about finance and feel with my low Hs gpa the only route to success in high finance is to get a MBA from a top school so any help would be appreciated