Special keyboard keys
The page up Key is mapped to fn + Arrow UP. 

Other key combinations with fn and the arrow keys are:


Arrow down > page down
Arrow left > beginning of line or begin of page depending on situation
Arrow right > end of line or bottom of page depending on situation


For the Insert Key there's no correspondant key on a Mac keyboard, but you could try using the fn + Enter which I found here. I can't confirm this though as I absolutely have no idea where I could test this out.