I am planning to do Ext 2 math next term (year 11 -> year 12).

My teacher was telling me that I wont be attending the advanced classes, and while the advanced classes are running, i am in another class doing ext 2 math. Is this normal? Im just worried that if i dont have the right foundation, I will heavily struggle with ext 2. In addition my school barely has given me any classes for ext 1 this year, and are refusing to give me extra classes, at the teachers expense (the teacher is happy to come early or stay late, but the school is one some bs saying that she isnt). Will i have 6 units worth of classes, and 4 actual unit? I know every school is different, but what is it normally like?

I have just skimmed over the table of contents for the ext 2 cambridge textbook and I have seen some notes, and It kinda looks like harder module 2 physics. I am rigth on this?