Where do I start studying for the IMO?

I'm a 14 year old and I want to go to an elite university, but to get accepted I need to show that I'm capable, and to do that I want to attend the international mathematics olympiad.

I'm very good at math, atleast I'm good at the Egyptian cirriculum, but I know that the IMO questions are extremely hard and require a more complex understanding of mathematics.

I want to study for a year and a half and attend the 2027 IMO. Where should I start?

Author: Secret_Fox1995