grade 12 canada

Immigrating to canada(ontario) soon and i am in grade 12........help needed?
okay soooooo
i am currently studying in Irish curriculum based school in Libya...and i am grade 12 hoping to complete my high school education in canada.
the canadian system requires 30credits and 40 hours of community work........i plan to go to university so i wish to take the 4U courses...
questions-1. will there be an entrance exam to see if i am capable of going into grade12......how can i prepare for it....how many subjects will they test me on.......is it hard.......how much percent shud i get on minimum
ummm........the course in my present school is very different to mcr3u course for math in canada.......
is have also completed igcse exams.......will they help me....
My score was 2A's,3B's and 1D
in grade 11 i scored on a 3 term average
math -97
english- 68
physics-95
chemistry-82
biology-85