How to suddenly start getting amazing grades in school

You educate your self by learning. Each one of us has a different system when it comes to learning. Once you learn something you will know how to use what you learned and when to use it. I was talking to someone on this topic a few days ago, if you memorized a bunch of stuff that's not learning, that's memory work, I mean look at those guys that memorized a shuffled deck of cards in less than a minute. I mean that's amaizing you can do that if you want to but that it's not learning also that guy it's never gonna remember what was the order of the deck from last week. Find something that you like and learning it's gonna be pice of cake.
Oh and there is also plan B if you're just for the grades. You can cheat🤫 it's not a good idea but you asked. So that's that good luck and have fun!