So you want to win the world qualifier? Well that's too bad because I am going to win it. Hopefully I can help you take second though.
Preparing for events is hard and it takes a bit more work than people realize. You have to dip your toes in and get a feel for the current meta, learn a bunch of decks, decide what clicks with you best, make a strategy around them and THEN you can actually get to tthe real preparation with your decks.