Moving to America for 11th grade

ok so backstory I guess, I was born in America and I am currently in the Philippines, 1/4 through 10th grade, my dad(who lives in america) asked me if I would like to study there for the rest of my high school years and maybe college, I said yes and told my mom about it, her immediate response was no, and after talking about she said fine but was very passive-aggressive about it. Now I kinda feel guilty for wanting to leave my mom and I'm worried about the different grading systems and how my past grades will convert.

also questions

classes that require 4 years to graduate, how does that work for me??

does homework really take 2 hours?