AP Questions + Self - studying

I’m currently in Grade 10 (sophmore) and I’m interested in studying AP Macroeconomics, AP German (German isn’t offered at my school, self studying German, I LOVE the language, completely obsessed with it, porbably A2 level) and AP US History. How hard would this all be?

ALSO, are you meant to study new AP subjects every year?
ALSO, in 2016 Jan, I’m going to do the SAT II German, French and US History - is this hard and with AP help?